So I was wondering, Is it theoretically possible for a gay guy to watch straight/lesbian porn and have an erection even though it's to women? Is it possible to even be turned on by that?
That's often a misconception about being gay. You can still get aroused by the opposite sex and still watch straight or lesbian porn. There's straight women who watch gay and/or porn and straight men who watch lesbian porn and some even gay porn (they just won't admit it). It doesn't change their sexuality. ANd it doesn't change yours. For some people they're still attracted to the opposite sex, but not enought to date or sleep with them, or are willing to if they meet the right person. It varies per person. So yes, it's very possible and a reality for plenty.
If that turns you on you -might- be bi. - This doesn't mean your 50/50 but instead could be attracted to guys a lot but women a very tiny ammount.
It works for me and I still consider myself gay. Guys are pretty sexual by nature so anything sexual is likely to elicit some kind of response.
There are quite a few lesbians who like gay porn, so why not? It doesn't do anything for me, but to each their own, and it doesn't make you any "less gay". Porn isn't the greatest indicator of your sexuality anyways. Like the above poster said, you could perhaps have a slight attraction to women as well, even if you don't necessarily want to have sex with them. According to Kinsey's experiments, the majority of people are bisexual (if only to a slight degree).