If he has any doubts about his sexuality, whether acted upon or not, they should not go through with marriage. He is obviously unsure and getting married can only prolong any hurt that may come in the future. They should do themselves both a favor and call it off!
As sad as this is, I have a brother in law who is LDS and he dropped same bomb on his family and fiancé right before the wedding also. He went to "counseling" for it and got married. She has since admitted her wedding night was one of the worst nights of her life and the first year of marriage was awful. They now have three kids and she has said many times, if she could go back without ever knowing her children whom she loves more than anything, she would do things differently. It still affects them and if he really feels that way, it always will. Do this Lisa, go to craigslist and go to the personals section.. Look under all the categories for men seeking men and all the "just wanna have fun" categories. This is something that is a part of her life now. Always checking. Always making sure he isn't on there looking for hotel fun. Go see how many men are on there with posts that's say, wife out of town and want for experiment. There are so many right here in the treasure valley it's SHOCKING. If I were you, before kids are involved, get out and find someone who pines for YOU. You can never compete with someone of the opposite sex. Don't forget that. Good luck to you and I pray God helps you with this awful decision you have to make.
If he has any doubts about his sexuality, whether acted upon or not, they should not go through with marriage. He is obviously unsure and getting married can only prolong any hurt that may come in the future. They should do themselves both a favor and call it off!