Is it normal to fantasize about having sex with men with no strings attached

I'm also a male in my early 20's and I consider myself a very sexual person. I have been with women and only women my entire life, but recently I been fantasizing about being with another man sexually with no strings attached. I've masturbated to pictures of men before, but that is far as I would go. When I'm really horny I get urges of being with a straight man only, but after I orgasm I want nothing to do with men or even think about being with them, in fact I feel disgusted with myself after masturbating to them. I believe I'm more straight than bisexual or gay, I don't see myself living as a bisexual or gay person, I have nothing againts that community either, it's just that I don't feel like I belong in that category. All my relationships have been with women and i tend to keep it that way since that is what I want in life, but the urges of having sex with men and strictly only sex sometimes gets in the way, obviously im confused about this and i just wonder if this is normal or not?