I masturbated my girlfriend by clitoral stimulation. I stopped masturbating her and I touched my penis. My penis had pre-ejaculatory fluid. (I heard it could contain sperm from the last time I actually ejaculated. It had been a full day since I last masturbated. During that time I also went to the restroom and took a shower.) Wiped it off on my boxer and proceeded. My girlfriend was on her period so she had a tampon but I might of just brushed by the string outside the vagina. She told me she washed her hands before taking it out. I never penetrated her vagina not even by my finger. All I was doing was clitoral stimulation. Thanks in advance for the help