My girlfriend and I have been dating for about 8 months now . I have a problem with other men being attracted to her . Her brother has this friend that really likes her ... and whenever we go to a party he is there . When we 1st started dating she told me about this guy , and how he really liked her .. and wanted to go out with her . It didn't bother me at the time because it occured before we were dating .. and he considered her single. But it's been 8 months now .. and he damn well knows that she is taken, yet he still flirts with her . I trust me girlfriend ... but I don't trust him . What should I do ?? I would like to make it clear to him that It bothers me .. without getting violent, so he will back off. :?:

Thank you for your time .