Without trust you cannot have a relationship ... and with children involved, ending a relationship over a kiss would be a bad thing. I know that in my first marriage, when my husband started kissing around and I found out, I was turned into a crazed monster. I would check his pockets, call his work if he was 5 minutes late, would have friends "spy" on him. For me this worked because he was cheating but it turned me into someone I hope no one else ever turns into. It was crazy and I was crazy. If it was just a kiss STOP talk to your Bishop and follow his council. But don't tell her if you truly stopped. It will make her crazy! Don't hide it .. but dont go running to confess.