"Is it gay for a straight guy to like anal sex?" I've heard this question come up a few times. There are actually a couple of different ways that you can take the question, so I'm going to address them both, and hopefully address all of your concerns in the process, whether you're the guy in question, or his wife or girlfriend.
Is it gay for a straight guy to like receiving anal stimulation?
That's the first way the question can be taken. So, either you're a guy who has discovered that you like playing with a dildo, or having your girlfriend or wife finger your ass, and you're having a bit of "gay panic" for whatever reason, or you are the girlfriend, or wife, and have recently discovered that your man enjoys some anal stimulation. Okay, okay... First of all, calm the fuck down. This, alone, does not mean that anyone is gay. It doesn't even mean that anyone is bi. Not in and of itself, anyway.
All men have the same asses. Gay and straight, alike. I imagine some people think that gay men have a special ass which experiences things which the straight male ass wouldn't, but that's completely false. We have the same anatomy, and can derive the same type of pleasure from the same type of stimulus. So, of course a straight guy can enjoy having his ass played with, or even penetrated.
What would be an indicator that you might be gay (if you're the guy in question), or an indicator that your partner might be gay (if you are the wife or girlfriend), is if the person giving the anal stimulation was another guy.
Being gay isn't about what you do, or so much what you like to do (sort of) but, rather, it's more about which sex you'd like to do things with, in relation to what your own sex is. So, no matter what you do, as long as the person doing it to you is of the opposite sex, it's completely heterosexual. Even if your wife or girlfriend is strapping on a dildo and fucking you up the ass while your legs are in the air and you're screaming "Fuck me! Fuck me! Fuck me!" you're still a straight dude getting fucked by a woman. And I don't care how much that dildo looks like a real cock. It doesn't matter.
Is it gay if a straight guy likes to fuck a woman in the ass?
This is the other way that you can take this question, and I pretty much already answered this, above, but I still wanted to address it, as a separate question, just in case. So, I'll break it down for you: "Is it gay if a straight GUY likes to fuck a WOMAN in the ass?"
Well, I think you have your answer right there. The guy is fucking a woman. The only thing... The ONLY thing that would make that a "gay" situation, is if the woman were a dude, rather than a woman. Since both parties are of the opposite sex. It's a heterosexual arrangement.
Does it fucking matter, though?
No. Look, I know you're all worried about being gay, or your partner being gay, and well, if this is the only thing that's making you think that, then you probably have nothing to worry about. If there's an attraction toward the same sex, then there's a possibility that the guy is bisexual or gay. Whether or not that's something to worry about... Well, as a gay guy, myself, I'm a bit biased. I'd say, it's quite fabulous, and hardly worth worrying about.