Hehe.
This sounds like my department.
First off I'd like to say that maturity has nothing to do with success here. You're not embarking on a science experiment.
Emotions probably have way more to do with this than you'd care to admit. For males, being_attracted == emotions. There's a reason why you'd be willing/interested in sleeping with this guy, especially if he's straight (ie. whats the point). If he is straight, you're setting yourself up for mild to heavy heartbreak and him for awquardness. Of course, the reason you're probably pushing this through is hope for the chance that he's gay. Oh, the eternal potential, and motivator of so many stupid but possibly rewarding decisions.
I think there's a good deal of wishful thinking going on; couple that with calculated self delusion and you've got the perfect recipe for either an uncomfortable or manipulative situation.
That being said, I definitely say go for it, especially if he's hot. Any straight guy can be coerced gay given the properly tuned situation and, as Tina mentioned, alcohol.
Do not attempt this without alcohol. Sleeping with him very well risks fucking up your friendship with this guy, and if that is the result than you had better at least get in a good round of uninhibited cocksucking. At least you'll have something fond to look back at, rather than a failed, awquard, aborted attempt at 'planned & sober' meat exchange; which would have the same if not worse results.
YAY
-jM
A&D