I'm pretty close (3 years older) in age with you and I really get where you're coming from. There have been friends that I've wanted to (and have) hooked up with. Let me be the first to warn you. You're "friendship" will never be the same.
1. you could end up dating and that's totally different than just being friends (one of the best feelings too and less awkward than most other dating relationships... you've been first dating for years)
2. you could become "friends with benefits" where when you hang out, that's all you're going to do it hook up, perhaps watch a movie. But there won't be anymore just pal-ing around. And you may feel extremely used, like he only calls when he wants a cheap booty call.
3. He'll be completely mortified and that's the end of the friendship.
4. (this doesn't happen very often) He won't want to and you'll end up brushing off the whole incident and acting like it never happened, and voila your friendship is all well and good.
So, my only advice is do what you feel like (your instincts) but be prepared to accept the consequences, whether good or bad.
In terms of telling if he wants to hook up as well, you really have to know how to read him. If he's acting differently than he has in the past. If you high five and he holds your hand that extra second, or a hug lasts a little longer than usual, or he won't let you catch him in his PJs, just silly things like that send of a signal of maybe wanting more than just a friendship. If you guys are really close, just sit down and talk about it. Don't make a big deal about it though, or you'll freak him out, even if he does like you.
