I suspect his friends are winding you up here.There is a serious aspect to this question - it is unwise to have unprotected sex- including oral sex - with someone you don't know very well. Consider that by exhcanging bodily fluids with this person, you are in effect 'having sex' with every sexual contact he has had - this is the primary route of sexually transmitted diseases. As Corkb says, get yourself checked, and make up your mind to have enough respect for yourelf to adopt a responsible attitude to your sexual activity. You have a righ to ask any man you don;t know very well indeed to wear a condom, if he refuses, that automatically disqualifies him from a sexual relationship with you. No respect - no contact. Easy, and much safer.