Did you ever have a best friend who you secretly lusted after but never dared to act on it in case they didn't feel the same way? That's exactly how Jimmy Little felt about his skater buddy Axel Ducharme.
Sure Joey Lafontaine has a girlfriend and there can be no denying that he's attracted to girls. But that doesn't mean that he can't find the occasional guy attractive. And more to the point, as he clearly states, he needs some penis sometimes.
Benjamin London likes the whole game of trying to seduce straight guys. The flirting with them and pushing the straight boy out of his comfort zone and seeing how he reacts, that's all part of the excitement.