Weclock: I personally am agnostic, but if I was of a christian faith, I'd probably believe that reproduction is a sin.
Then you do not understand Christianity. Try reading Genesis 1:28 where God's words to Adam and Eve are, "Be fruitful and multiply."
Nafe: I very much doubt a gay guy could turn, just as I couldn't turn gay. I could technically perform the acts, but that wouldn't make me enjoy them or actually be gay. Though in the situation you explained above I guess it might make sense to conceal their sexuality, but that wouldn't change what they are. I expect that's what you meant and I'm just being pedantic.
This sounds good on the surface, but it is like saying, only those who steal habitually or like it are, real thieves. But for you, if you went through the act of stealing and dislike it; then you would not be a thief.
If I steal I am a thief even if I say, "But I did not like it while I was doing it".