What Should I do?

Okay, so I’m talking to the guy and things are moving forward but he told me about a bad relationship he was in where his girlfriend cheated on him with his best friend.

After the breakup, he was in a low place and had sex with at least 9 people. I mean I know there’s safety and all but I’m not sure if I want to do it with him anymore. That’s a lot of girls he’s been with and he’s clean but I could be the first one to get an STD or STI. I’m not sure what to do.