Where is my better judgment in men??

I had a one night stand with someone I knew back from high school. I didn’t plan it, but I think he did. We went out for drinks on a rooftop bar that was “coincidentally” attached to a hotel and he booked a room. I was feeling awful, I had just thrown up, but no I wasn’t drunk. He initiated the sex and I saw him put a condom on and next thing I know, the condoms on the floor, he took it off. Right after the sex, he took out his phone and showed me that he got tested for STDs and everything looked negative, he did that because he knew he took the condom off. He told me that he wasn’t going to have sex with anyone else and that he wanted to be FWB. And somehow I got an STD which I’m sure was from him. He also asked if he could use my paystubs to get himself an apartment. He gets around using his friends cars. He doesn’t have a job, apparently he’s a scammer.. Where is my better judgment?? I suck when it comes to my choice in men. Obviously never seeing him again even though he called, begging to have sex with me again. It’s so hard finding someone that’s serious and wants to settle down, but now I know casual sex isn’t for me. And I don’t think that he slipped me anything but you never know.