NeedleinA

While I can appreciate the sentiment that all of you are trying to express, "shelter the wife and help her avoid future pain", those that only follow this line of thinking are fundamentally missing the point of why he should be telling her to begin with. 
It appears we are only focused on the possible/probable "future pain", and that we are creating a convenient excuse for not apologizing for "past pain". Talking to his wife is first and foremost for her benefit, not his. A chance to help make her whole again, you know the person that was actually wronged during the marriage. Him being able to offload his personal guilt is only secondary, but not the primary purpose. Restitution is about making right/helping/healing the "other" person. By healing the other person, the sinner is then able to truly unburden himself of his guilt. By not telling his wife, he is doing a disservice to both parties. 
I think the hold up for most people is the subject matter involved. The matter of pornography is a subject that hits home for many people, and as such we look for any possible loophole we can find. We are human, I get it. If we were talking about a wife not knowing about her husband's past drug abuse problem during their marriage, I think most of us would have a much clearer perspective on how we would handle things.
The wife deserves and is entitled to an apology, an apology for his: spiritual absence, his physical absence while off viewing porn, his diminished affection towards her, his decline in patience and long suffering with her, his reduced tenderness during intimacy, his desire to place his needs above hers, etc. etc. 
If he didn't actually hurt her during the time of his porn use (which appears to be the defense), why then the fear to tell her about it all? If she wasn't hurt then, why would she be hurt now? Hurt from what? Either the porn user was so incredibly good at hiding things that the wife had absolutely zero clue...OR...she always knew/felt something was off/wrong but she couldn't figure it out, and so she blamed herself instead for all those years. Why aren't I a better wife? I wish I was more attractive? I must have done something wrong because he is short tempered with me again, etc. 
One school of thought is: Don't tell her ever.
The other school of thought is: Do tell her at some point. She deserves an apology. There are wiser/smarter times than others to have this conversation. I would suggest the best time to do it is when the Spirit tells you, "this is the time". If the OP says "I feel like I need to talk to her", then who are any of us to tell him not to?
Everyone benefits from this apology. While we might measure the success or lack thereof only by the immediate or short term feedback, we need to view this in the eternal perspective. In the long run it is better for both parties.

Gospel Principles Chapter 31:
"When we speak untruths, we are guilty of lying. We can also intentionally deceive others by a gesture or a look, by silence, or by telling only part of the truth. Whenever we lead people in any way to believe something that is not true, we are not being honest."
"Honest people will recognize Satan’s temptations and will speak the whole truth, even if it seems to be to their disadvantage."
 

I don’t know your wife. So imma throw my lot in with those who say to pray about it and do as the Spirit directs. However, if it were me, I would want to know. If my husband came to me and said here’s what I did wrong, here’s what I did to make it right, and here’s how long it’s been since I’ve done it, that would foster in me nothing but respect and even trust. In fact, something similar has happened in my marriage (not with pornography, it was something else). And I was hurt, but mostly because he felt like he needed to shelter me from it for so long. This was a family/couple matter, and he felt like he needed to take care of it himself and then not talk about what was going on. I am a woman, but I’m not a baby. I’m a partner—a helpmeet—and I was hurt that he wouldn’t bring this matter to me so we could deal with it together.
We women get human nature. We have it too. I don’t know if your wife will see things this way, but that’s how I see it. I understand you’re dealing with some emotionally charged issues here. But, quite frankly, sexuality is a couples matter. As your wife, your sexuality is her business just as hers is yours. Every couple out there has had issues and things to talk about regarding this aspect of marriage. A wife deserves to know what your struggles and issues have been, even if they are in the past.

Your definition of adultery is wrong.  The True to The Faith book says, "The Ten Commandments include the command that we not commit adultery, which is sexual intercourse between a married man and someone other than his wife or between a married woman and someone other than her husband."
The woman in the verse doesn't necessarily have to be married for it to be adultery.  If the man were married and the woman not married, it would also be adultery. 
 
 
In the LDS guide to the scriptures on lds.org ( https://www.lds.org/scriptures/gs/adultery?lang=eng) it says this about Adultery: "The unlawful sexual association of men and women. Although adultery generally refers to sexual intercourse between a married person and someone other than his or her spouse, in the scriptures it may also refer to the unmarried. "
 
In the Church today, that's not how marriage works.  Having sex with an unmarried person is NOT the performance of a marriage ceremony.  Marriage must be done beforehand.
 
Here's a scripture that teaches that a married man lusting after another woman (doesn't matter whether she's married or single) is sin:
D&C 42:22-23:  “Thou shalt love thy wife with all thy heart, and shalt cleave unto her and none else. And he that looketh upon a woman to lust after her shall deny the faith, and shall not have the Spirit; and if he repents not he shall be cast out.”
 
I suggest in your studies of these issues, you rely heavily on the basics such as these:
For the Strength of Youth : https://www.lds.org/youth/for-the-strength-of-youth/sexual-purity?lang=eng
True to the Faith: https://www.lds.org/manual/true-to-the-faith/chastity?lang=eng

(Answer:) 
Elder L. Whitney Clayton:  "Along with losing the Spirit, pornography users also lose perspective and proportion."
Elder Dallin H. Oaks: "Pornography impairs one's ability to enjoy a normal emotional, romantic and spiritual relationship with a person of the opposite sex... It impairs decision-making capacities"
There are wonderful members of the church who struggle with pornography, some even right here on this forum. We pray for one another as we each fight our own personal battles and do the best we can. As we strive to choose the right, may we not let the Father of all Lies deceive us into thinking that the issue of pornography doesn't affect others around us, especially our spouses.

Wish i could be there for it.

Response #1:
 
 
Response #2:
 
 

Is Mirkwood in your friend's ward?  Because if your friend got all buddy-buddy with the one guy who everyone knows comes to church packin' heat, I bet the problems would clear up in a hurry. 
An armed society is a polite society, and all that.   

The carinessa tops and bottoms are more form-fitting and make me feel less "frumpy" in other styles. I'm really petite so everything drowns me, so the carinessa is really nice to have if you want a more fitted look that works with your figure. Maybe that might help! 
There's a lot of good advice on this form though about the importance of the garment---and even when we're living righteous lives and attending the temple regularly, we sometimes need that reminder of what the purpose of this garment truly is. 

Elder Richard G Scott, April 2000 General Conf.
https://www.lds.org/general-conference/2000/04/the-sanctity-of-womanhood?lang=eng

"A husband must have no private, hidden agenda that is kept secret from his wife. Sharing everything about each other’s personal life is powerful spiritual insurance...One of the most damning influences on earth, one that has caused uncountable grief, suffering, heartache, and destroyed marriages is the onslaught of pornography in all of its vicious, corroding, destructive forms. Whether it be through the printed page, movies, television, obscene lyrics, the telephone, or on a flickering personal computer screen, pornography is overpoweringly addictive and severely damaging. This potent tool of Lucifer degrades the mind, heart, and the soul of any who use it. All who are caught in its seductive, tantalizing web and remain so, will become addicted to its immoral, destructive influence. For many, that addiction cannot be overcome without help. The tragic pattern is so familiar. It begins with a curiosity that is fueled by its stimulation and is justified by the false premise that when done privately, it does no harm to anyone else. Lulled by this lie, the experimentation goes deeper, with more powerful stimulations, until the web closes and a terribly immoral, addictive habit is formed.  How can a man, particularly a priesthood bearer, not think of the damage emotionally and spiritually caused to women, especially to a wife, from such abhorrent activity? The participation in pornography in any of its lurid forms is a manifestation of unbridled selfishness."

I've struggled in the past with questions... and such sites have me running back. The whole vibe "oh, of course you can stay LDS all you want and we won'the judge but we will anyway because you're naive and don't know this and that and this nugget of irevalant fool's gold but yeah, you can be LDS!" Is just so disgustinhly patronizing for those with real questions.

Wear whatever bra you want. You can wear bras next to your skin and not over your garments. I find that if I wear bras over garments that I have the issue of the bra sliding around and even losing the purpose I wear it. So, I choose to wear underwear next to my skin and under my garments. I can honor my covenants and still wear undies underneath my garments.
And wearing cute/sexy underwear doesn't make me feel feminine or ugly. It how I feel about myself that gives me confidence and feelings of femininity or sexiness.

This sentence really bothers me.  If your self esteem depend on clothing.... that's a problem that is not the fault of the garments or anything religious: your INCREDIBLE value as a person is NOT dependent on any clothes.

Underwear does not a sexy, feminine woman make. Outerwear does not a sexy, feminine woman make. What makes a woman feminine is your attitude, the way you present your self to the world. How you treat others. What you think of yourself.
My mother was probably the most feminine woman on this earth. She was not LDS until very late in life. BUT her underwear was utilitarian, IOW it served it's purpose. Boxy, old lady kinickers, bra that was downright ugly. Slip that was no more than 1 inch above the hem of her dress. Yes, she wore dresses and never, ever pants/slacks. Even her shoes were ugly. She wore them to protect her feet and give support to her arches. 
When Mom came down the stairs in the morning, the look on my Dad's face was pure love. He adored her. NOT the underwear she wore. He loved her modesty. Had they been LDS when us kids were growing up, they both would wear their garments and never thought once whether they were sexy or not. 
 

The Scripture are full of council of what we should when we hurt someone...  That is God's Law... The fact that you are twisting yourself in knots trying to avoiding this simple fact is telling...  Now you are saying the wife is not hurt because she lacks knowledge of the sin in question...  And I would agree that she is not hurt... yet...
But the scriptures are quite clear that all secrets will be revealed and shouted from the roof tops...  The day will come when she does know...   And when that day comes does he want to compound this sin with the sin of lying (the scriptures are quite clear where the liers are thrust) and deceiving her about it for however long the time difference is?  Does anyone think that postponing the wife gaining the knowldge (because we are scripturally promised she will gain that information) is in anyway wise?   

No apologies needed at all! Keep on posting and keeping the threads going!

Yep.
Today we made 3D shapes from paper (I defend this in the name of geometry), colored, and then cleaned out our chair pockets and cubbies in the name of finding the three writing finals I was missing but was really just a step in getting us out of here next week.

Is this why when I ask my kids what they did for the last 2 weeks of school, they say: "We played games, ate popcorn and had long recess all day"

@Eowyn
Mention it to the Bishop. Then in a couple of weeks she will be called as the speaker in Sacrament on "Kindness towards others". She will repent and come and apologize to you for her actions. Also... ask to have her called as YW secretary so she can sit in on Presidency meetings and learn how YW really runs.
Oh...just kidding... go @mirkwood on her!!

It sure can be. It is much easier to repentant in "secret" than it is to face the person your hurt. This is why it is so easy to try to justify not telling the offended person..."because of not wanting to hurt the spouse's feelings".  Make no mistake, the spouse has already been hurt by pornography. Now they deserve to understand the truth and origin of that hurt. They deserve to know why they were treated differently back then. YES, they were treated differently, just like they are treated differently when someone is suffering from depression. 

It sure can be. It is much easier to repentant in "secret" than it is to face the person your hurt. This is why it is so easy to try to justify not telling the offended person..."because of not wanting to hurt the spouse's feelings".  Make no mistake, the spouse has already been hurt by pornography. Now they deserve to understand the truth and origin of that hurt. They deserve to know why they were treated differently back then. YES, they were treated differently, just like they are treated differently when someone is suffering from depression. 

Relationship-to-relationship a spouse's reactions may be very different to the viewing of pornography. I've seen some spouses react with great hurt and alarm, and I've seen some wives and husbands basically say "whatever thrills ya".
Neither reaction relieves the viewer of his or her responsibility to bring their habits and desires within the bounds the Lord has set, but an understanding reaction opens up communication channels and goes a long way in helping a person walk away from the temptations in a step-by-step manner.

Nah, I don't believe in summer school.
I've entered blissful zen and have stopped caring.

And hence prayer and personal revelation.  Do what the Spirit tells you, not what a bunch of strangers on the internet say.  (And realize that there may be more options than "tell her" and "don't tell her".)

His porn usage was a transgression against his relationship with his wife and confession to her is a required part of repentance, not an option.  Stopping the behaviour is wonderful, but by itself it is not being fully repentant. 
D&C 58:43  - By this ye may know if a man repenteth of his sins—behold, he will confess them and forsake them.

Yes, there is a good chance her feelings will be hurt, perhaps a lot although I think the circumstance, change of behaviour, and voluntarily confessing would do a lot to ease the blow.  Even if it takes some time for her to work through that it doesn't justify hiding it from her. 
Once it has been worked though and she has forgiven him and they reconcile they will have a better marriage than before, and he will know that she loves him knowing it all rather than wondering if she would still love him if she knew everything.  Much better than living your whole life with a secret shame and guilt.