This should be exciting 
I’m all for specifically LGBT-related games 
(By the way, if you’re here because you’re interested in gay-themed games and haven’t checked out this poll, you may want to make a vote for The Beast Within Every vote counts!)
With regards the MC’s age—is this the sort of thing where there might just be a time jump? 
Like, if you want the main character to start dealing with these feelings around the age of sixteen, but then be eighteen by the time more explicit stuff is happening? I don’t know what kind of time frame you’re looking at
Yeah, I don’t think I really felt any attraction to boys until I was about 12, and even then it was pretty mild until puberty hit more around ages 13 and 14 I really just hadn’t developed the interest yet before then.
And it wasn’t until I was 17 that I actually started acknowledging these attractions… so yeah, teenager figuring these things out would be very close to my experience 
(I bumped into a cute guy once knocked the wind out of me, to be honest. Was less pleasant than one might hope )