I've never been pegged but I fantasize about it every day. My wife sometimes licks and fingers my anus while I masturbate at the same time, but she's drawn the line at sex toys. I've had many long sessions alone over the years with dildos, butt plugs, and other sex toys going up my ass, often while I watch porn with pegging, rim jobs, and anal fingering (anything with men on the receiving end of anal stimulation by women). I've had a fantastic time and incredible orgasms from anal masturbation. I love the idea of gender role reversal, with the woman being assertive and me receptive. For me, the two sexiest images are a beautiful woman, naked or in lingerie, wearing a strap-on dildo, and me, naked, face down and ass up, ready to be fucked like the slutty bitch I am. Or the good boy that I am, ready for my reward.
A desire to be pegged doesn't mean anything necessarily about a man's sexual orientation. I do, however, think about men sometimes, almost always with me in the passive role, sucking cock and taking it up the ass. Sometimes those fantasies combine with female domination, as I imagine having sex with a woman and a man at the same time and she's directing things and basically using him as an instrument to play with me, to fuck with both my body and my mind. In reality, men don't turn me on. I see men in person and the idea of sex with them doesn't interest me at all. Fantasies are different because my actual inclinations don't limit where my thoughts can go. The situations are implausible: the guy is incredibly good-looking, the woman as well, but what really turns me on is her intelligence and power and the idea of surrendering to her so completely that I will not only suck cock, eat cum, and take it up the ass until he shoots inside me, but also enjoy it thoroughly.
So I'm straight but not narrow and I enjoy my fantasy life without guilt or misgivings. And I'm very anal erotic.