You know what's gay? Exclusive attraction to the same sex. Don't get caught up on labels and shit like that.
As far as girls into strapons, i've dated one, maybe two girls i would've trusted with that. Never got that far with any woman, and it (butt play) is far less of an interest than when i first got into it.
Regarding butt plugs, i started with these

Ironically, i don't think Toys in Babeland (their packages arrive in discrete brown boxes with "T.I.B." as the sender) even sells those anymore.