Does he have another woman? The question is fundamental in if you want to further serious relationship. If it's sex for one night, what's the difference - if he was married or have a girlfriend. It all depends on your life principles.
Will sex safe? Of course, this is a very sensitive issue. No one wanted to catch a sexually transmitted disease. Extremely and risk to have sex without contraception, but with the unfamiliar guy better to do it in a condom.
Why is he? If you're a girl free manners, and sex for you only sports, then there could be no difference - it's just another trophy in your collection. If you are depressed, you just break the relationship, you should not jump into bed with the first comer man. The pain will not go away, will only get worse. Some are motivated to take revenge on her ex. This feud is not practical, because the relationship ended.
How well do you feel? You are wearing everyday neerotichnoe underwear, shaved legs bad and no intimate haircut? Then it is better to postpone sex. Joy and peace of mind it will bring. This sex can only develop new complexes - nothing more.
How will you feel the next morning? This question often helps not to take hasty actions. If you went to bed with him out of pity and compassion, the next morning, but the pain and hurt, he did not bring, and you yourself will feel uncomfortable. Have sex only with people that you like now, not in the long term.
What if you change your mind at the last moment? Honestly and openly explain to him that you do not want sex now that thought again and you need time. If you are shy by nature, and such things difficult for you to speak out loud, then refer to the banal headache or an unexpected call a friend who so need your help.