It does not make you gay at all for liking anal stimulation/pleasure/p enetration with a toy. I used toys quite often of various kinds and love it.

As far as your girlfriend being weird about it, do you personally think she will? Do you know her well enough to know if she is into anal play? I'd say tell her only if you feel you really want her to know.

Depends on what about sucking penis you fantasize about. I think if it's the male body attached to the penis or the male orgasm that would result, then you're probably at least bi. If you just want the weight and feel of it in your mouth, maybe find a girl who wants you to suck her strap on. There's plenty of girls who like pegging a man. Something like a Feeldoe or a Share would probably give her pleasure if you sucked on it too, so that's a bonus, or you could get a good realistic dildo for her harness if you want something that would really mimic a man's penis.