Orgasm to early? I pull away

When I am having oral sex with boyfriend I really enjoy the feeling of him being down there, so I have an orgasm after having an orgasm I can't stand him touching me down there anymore or even caressing my breasts is this normal? He doesn't really say anything to me but, I leave him without pleasing him. I just want to stop.. If yes what can I do so I don't pull him away after orgasm. What can I do ?