Hi I met a guy and we mutual masturbated. We didn’t touch and we orgasmed on own chest and was very careful not to contaminate each other with fluid. I believe this is zero risk. However he got me a towel, the towel was clean but I’m worried semen from his hand got on the towel. I then used the towel to clean my penis. I am very worried I’ve put myself at risk after being so careful with the actual sex act. Can anyone advise.