Speaking for myself, depending on the type of kiss my wife plants on me can determine wether or not I get excited. If she gives me quick kisses then no reaction. However if she gives me slow sensual slip me the tongue kind of kisses, those make the difference and I get excited. If your best friend and her crush were making out with all kinds of french kissing and ear nibbling, etc, then it's no wonder the guy got a boner. Kissing CAN be considered a form of foreplay. If you and your partner are heavily making out, you don't get excited?
whoever said kissing is sexual is stupid. sometimes yes but usually no.
i get boners pretty easily sometimes from stupid things... sometimes the vibrations while riding in a vehicle set it off... and even when using one of those non-mobile bike workout machine things at a gym-just the way my shorts rub against my junk. getting a boner doesn't only get set off by sexual things for some guys.
but at the same time some horny bros get boners simple from making out.. they can't help it
I look at it this way, sometimes (particularly at the start of puberty) guys really don't have any control what so ever over their erections, in the same way girls can't really prevent/control there period from coming. And no I'm not saying that getting boners for guys is worse than having your period for girls, trust me if blood came out of my downstairs I would totally freak. I really have sympathy, respect and appreciation for you guys. :D so yea erections in guys are something we sometimes just can not control so don't start laughing or making it out that we're gross for having it, I bet you'd hate it if you were making out with your boyfriend (I know this isn't the same thing but it's relative) and you just happened to be on your flow and he noticed and then screamed at you, 'what the hell' you're so gross! Then he went and told all his friends about it?! And us guys get called insensitive?!
Well which would you prefer, that we get boners too easily or too difficult? And anyway, its a f*cking bodily function. Guys who are straight to the point of being homophobic will get boners from being given a prostate exam, doesn't mean that they're gay. It's like asking, why, since women get wet while they're being raped, that they don't like it.