Sdmjwg811, You should not do anything. He is man enough to keep his penis inside you. He should just push back and continue if that is what you ant him to do.
Your vaginal muscles will tighten around his penis when you orgasm. He should find this very pleasurable and some men will just orgasm when they feel that.
Have you spoken to him about it? He might be just withdrawing to look at you having an orgasm. Most men will get a lot of pleasure from seeing you enjoying yourself so it is not unusual for him to take a pause to enjoy your orgasm with you.
I've had this problem with my boyfriend too. It seems that when I come close to orgasm, the muscles tighten and push him out. I don't think it is just that he's not 'man enough to keep his penis inside' me. lol He's not very small either. He says that he really doesn't like it when it happens, like he's not pulling back or anything. I don't know if I am too tight or too loose or what.