In a college biology class, the professor discussed pregnancy and birth, and he mentioned that circumcision was something that could be done to boys. After the lecture, a female student asked something about circumcision. I was sitting near the back and she was pretty much front row, so I didn’t hear her question. But the professor answered that no, it’s not dirty or gross, and in fact perfectly normal to be uncut, and she wasn’t at risk of more STD’s or anything like that by having sex with an uncut guy.