This is exactly what's been flowing through my mind this whole time. The first part was spot on. In regards to the second, the only part that I question is his actual confidence to initiate. Sort of like that, "we're both waiting for the other person to say I love you" kind of thing. (but not in that pretext) Since it'll be the last time I see him for a while, or maybe even ever, the fear I have about "messing things up for the future" is definitely decreased. I think what I've come to so far is that if things go as they usually go, I'm just going to speak up and say something. Initiating something physical without knowing if he's on the same page or not feels wrong in a sense. I know people do it, and I know it does have success, but for me I think saying something would be the better route. Something maybe like "hey, I know we play around a lot and have fun messing around, but since it's my last night here and we won't be seeing each other for a while, if you're interested in trying something a bit more, I'd be open to that". Or maybe something around those lines?Straight bros can be very affectionate with each other. Hugging and being playful, even naked or in a homoerotic way are pretty common among jock types. That doesn't mean he's gay or bi at all. It just means he sees you as as his bro, as one of the guys. Personally I wouldn't recommend trying to initiate anything more unless you're willing to possibly ruin your friendship. (I doubt he'd drop you altogether, but if you make him feel uncomfortable you might just grow apart)
Just think of it this way: if he is bi or interested in experimenting, and he's interested in doing that with you, he will try to initiate. If that happens you can just be completely receptive to it and see where it goes. The upside of this approach is that you'll feel great if it actually does happen - you won't have to worry about feeling you 'tricked' him or if you did something bad that damaged the relationship.
Geez I feel like such a little girl. If you guy's knew me in person and heard me say this, you'd all be like what the fuck Jarren.