Cut on your finger and you got semen in it?

Okay but an important piece of information is missing. You can only get a blood-borne STD if the guy is infected with that STD! If you don't know or are not sure of his HIV status, you should insist he use a condom! In any event, too late now, huh. Wash your cut with warm water a soap. Pat dry. Put an antibacterial ointment on it. Lastly, remember the concern you felt about this---and insist a guy wears a condom.