Confused, and need advice

So I am not totally sure if I'm gay. Im 15, and a sophomore in high school. I had a huge crush on this girl in 8th grade, but since then I haven't really had much interest in girls. For one, I totally don't get the attraction of boobs. Like at all. I do definitely find guys attractive, I definitely want to have sex with a guy at some point. But I also go to an all guys school, so I'm not totally sure if I'm actually gay, or in a sort of brainwashed state. Also, I can totally admire a girl. I can recognize when one is hot, or pretty, but it's not necessarily sexual. My mind does tend to flip flop between, Im totally gay, Im not gay (maybe bi), and Im probably just brainwashed due to the all guys school. But then when I was porn, its gay porn about 95% of the time and when I do watch some straight porn, im not generally as turned on as i am by gay porn. Anyway, I just have no idea what's going on and was wondering if you all have gone through this, how it turned out, and a second opinion without emotional connections. Also, I have a friend, that I know is gay. Our friendship has also been kind of weird over the years, not bad, just different than all my other guy friends. Id be totally fine with being out, at least to my friends and stuff, and am totally comfortable with being gay, I just don't want to come out and realize that Im not gay and have it all be fucked up. So should i tell him? And what other advice do you have?