I think that with this question it is important to remind people that I don't judge anyone. I take every question or every concern with the utmost respect and you can always feel free to ask me absolutely anything. I'm your safe zone because everyone fucking needs one sometimes.
I can't decide if you're asking if you should be concerned that she is bisexual or if this will effect your sexuality in anyway. Either way, the answer is absolutely not. Pegging has no bearing on anyone's sexuality. Straight men are still straight. Straight women are still straight.
Two things to note:
Pegging can be very empowering for women. It is a nice power exchange that allows the woman to take control and can be paired with strong fem-dom play or it can just be very sensual role reversal.
I know straight men and women who absolutely love it*. I'm an advocate for it and I would be happy to walk anyone through getting into it and set up with it.
Why are people so afraid of the fluidity of sex and sexuality, anyways?
*I also know bisexual, bi curious, and gay men and women who love it but that is obvious. But there are gay men that don't like it, for what its worth. Like I said... it isn't sexuality based.