Too many guys on this site are so hung up on the guilt of having any sexual attraction to men, no matter how small. Just be comfortable with who you are and so long as no body is getting hurt, enjoy what ever tickles your fancy. It doesn't make you gay or bi. Only you can deside that for your self. And if you did come to the conclusion that you are not 100% straight as an arrow so fucking what, there is no shame in that, be proud of who you are and enjoy it to the max.
( And come on! gay porn is fucking great. I urge all men to sample some. Seeing two fit young bodies having such intermate contact is hot no matter what sex the might be)