Although this is fantasy, I probably could do it.
I am a man that was not blessed with a body like Adonis. I am actually quite petite. So petite in fact, that if I put on a wig and makeup I look just like a woman. I'm not gay at all, but I have learned how to take advantage of this unique characteristic I have. I joined a gym, not as a man, but as a woman. No one can tell the difference. I go either late at night or early in the morning when it's not too busy. I go into the women's locker room and just sit there as if I am dressing to work out. Of course I am surrounded by half naked and completely naked women.
I used to have to find an empty stall to jerk off in, but I now just stick my hard dick through a hole I cut in the bottom of my gym bag. I can reach in like I'm looking for something but really I'm softly stroking myself. They provide me with a towel that I can cum in to. There are a lot of unattractive women there, but it's worth it to see just one perfect sexy woman naked right in front of me as I please myself to her...and she has no idea.