I am anxoius about having sex more than once in a night. When sex is over and the condom is disposed of, some sperm remains on the tip of my penis. For contraception purposes, it doesn't particularly seem safe to put on another condom before having sexual contact again? Some sperm always gets on my fingers, isn't there a chance my girlfriend can get pregnant if my fingers enter her vagina? Also if we masturbate each other afterwards, aren't we spreading the sperm on our fingers and increasing the risk of pregnancy? Should I be washing my penis and hands each time after we have sex in a night?