It is not very common, I don't think. I illustrated the two extremes on either side of the spectrum but I am sure it is like a bell curve and the vast majority fall somewhere in the middle.
Unfortunately, it seems that not embracing some lifestyles is seen by some as condemning and judging, though, so there may not be much functional difference.
For example, my parents in law told their oldest daughter that she could not show any PDA or sleep in the same bed as her married lesbian partner at their summer cabin where the extended family gathers for reunions each year. They did not take that well and chose not to come at all and distance themselves from the rest of the family, for the most part.
That kind of situation makes it very hard to show love to the person but not condone their behavior and lifestyle.