HELP!! PLEASE!!I'm a 15year old guy, currently on my Junior year, am i...

...gay or homo if..? i have a friend, we just met this year, we became close starting the time when his best friend left him, he had a crush on a girl, he has been courting her for a while, same goes for me,i've been befriending my crush (a girl), but sometimes, when we get together i joked him like having sex or what, we talked about masturbating and sometimes i get a boner when he tells me how he does it, here is my point, there is a lot more guys more handsome than him, but why am i "attratcted" to him? and why am i still attracted girls? sometimes i even get jealous when he is not going/staying with me whenever he have free time but instead going to his girl..