I am a well-adjusted late twenties male with a steady girlfriend. Lately, I have been increasingly fantasizing about various types of anal penetration. I have discovered that during masturbation, this brings me very intense pain/pleasure. Even though I think it may be satisfying to experiment with a vibrator or other objects inserted by my girlfriend, I find myself drawn toward trying the real thing (i.e., having anal sex with a penis). The problem is, I definitely do not consider myself homosexual and, in fact, the thought of the actual act with another man actually repulses me. Am I trying to have the real thing without going through a bisexual experiment or what?