Well I met a guy yesterday and we ended up having sexual contact. I used my left hand to masturbate him, then my right hand. He told me he precums a lot, I think I felt some on my my palm of my left hand not sure if there was any on my fingertips. Anyway I had a cigerrette 10 minutes later but touched quite a few of them, so could I catch anything? I'm more worried that my siblings might have caught something because my brother and sister smoked a couple of my cigerrettes without me knowing so could they get anything? I'm not sure if he had an STI or STD but he said he hasn't.