Why are some men some immature lol ?

I was talking to this man for a brief period (more like boy but he’s 32 so I’ll call him a man.) We recently began speaking again just casually as I told him I am not interested in having casual sex but we can be friends. We were talking about exercises and he said I should get some of my steps in for the day because we talked about that the night before, which I said , “Probably won’t happen today I’m going to go home and lay down with my heating pad, my uterus is dying.” On which he replied, “Jesus. TMI.” I’m sorry lol but Is there anything I said that was gross?? I didn’t bring up blood or anything I just said I had really bad cramps and my uterus hurts? This is the same guy who can show me pictures of his dick all day long and how he wants to use it, but when I bring up a normal bodily function it’s all of a sudden TMI? I can’t stand immature men 😂😂