Sex and sexuality isn't always as straightforward as slaping a label on an act as straight/gay/bi or on a feature as masculine/feminine. Sexual and romantic attraction are complex things.

In this example male homosexuality and anal play might have a bit of an overlap, but the two are distinct. You'll find on this subreddit in particular that straight men can be completely into either giving or receiving anal. Not every gay man is into butt stuff, and not everyone who is into it is gay.

The only thing here that implies he might have some homosexual inclination, in my opinion, is if he's watching gay porn (by "porn with gays", I'm guessing you mean two men having sex), but even that isn't a sure thing. Porn is sometimes kind of an exploratory thing.

What does matter is that he is choosing to be with you.