Hey confusedgf. Def has offered you some great suggestions and perspective. Let me offer you some perspective of what I think your BF may be going through (Def knows about me, and my experiences - I started my own post here last year when I was going through some crap!).
I've just turned 48, and now identify as a gay man. Well, actually, I've always identified as a gay man (since about 12) but lived the life of a hetro man. I was forced (by failing mental health) to "come out" to my wife of 20 years last May. It broke my heart, believe it or not-I do love her with all my heart-which makes it harder. I hid who I was for my entire life, fearing rejection by everyone I knew and loved. It came to a point though that I'd fallen so mentally low that I questioned,daily,on the best way of stopping the pain, and yes that meant what it sounds like.
My wife knew I was unwell, as did my 2 beautiful kids(17yo son and 10yo dghtr). My sex life was non-existent and had been like that for most of our marriage. My wife just put it down to having low sex drive, but of course I knew better. I didn't want to lose her.
Your BF probably knows the truth deep down - whether his is Bi or Gay-but may just be too afraid like I was.
I wish that I had come out years ago, even if it had been after I got married. I've got wonderful kids and I had 20 years of wonderful marriage. But now I live with the guilt that my wife is now also single as she approaches 50, at a time in her life where she should be enjoying seeing our kids turn into fine young adults, and dreaming of the worldly travels as a mature woman with her loving husband. I live with that everyday, and so does she. Fortunately, like you, she is a wonderful caring woman and her first concern was my health. I only moved out in November, so things are still quite fresh, but she is my best friend and my hero.
All I can say to your BF is to look deep inside himself, and ask what does he want for HIMSELF, and what does he want for YOU? I was selfish and afraid in a time where society made it tough, but nowadays it aint so bad.
Def last sentence on the last post about counselling is the best advice anyone can give you. For your BF, he should call QLIFE - they are a peer based LGBT phone counselling and can refer him to a LGBT friendly counsellor. They will help him work through his thoughts.
Make the right choice for you, you both need to. There are consequences to making the wrong ones, as I well know.