Ask yourself honestly this question first: Are you a slut?
If your answer is yes, then jump right in and proudly go through a string of meaningless sexual relationships. Don't let anyone put you down for being yourself. Own up to your behavior, and desires without shame. Don't let him tell other people about it, you tell them first, and give them all the gory details about his performance as well. It sounds like he would have no problem doing the same to you because he is a male slut, and yes, many men are sluts too.
If you are not a slut, then stay away from him. Since he is a slut he will never respect you for giving in to his slutty behavior. You will just be another conquest dissected in gory detail for the entertainment of his friends.
My basic feeling is to think about the person you most respect in your life (a parent, grandparent, teacher, minister, etc.) and think about how you would feel telling them honestly about what you did with this guy if you go through with it. Does that scenario seem like an affirming one, or an embarrassing one. Let your feelings about the eventual consequences be your guide, not your feelings of the transient momentary pleasure.