Today after I finished working out I went to the showers at my gym. I am not modest and walked with my towel over my shoulder. I got into the shower stall and started showering. A guy that was changing came into the shower area fully clothed and looked at me. He then left and came back 1 minute later and started showering. I didn't think much about it until he started moaning. I looked over and he was jerking off. I was done showering and dried off and then walked out of the shower and told him to enjoy the rest of his shower. Has this happened to anyone else before? Any recommendations? I really don't care if someone watches me but not interested in having them moan and jerk off watching me.