i feel like im going to pee during oral sex?

[Tiffany]

so ive never had an orgasm before. and lastnight my boyfriend ate me out for the first time and it was getting super intense and i felt like i needed to pee...like REALLY bad, but i went pee before we started doing anything. so i told him to stop because i didnt wanna pee all over his face or something. why do i feel like i need to pee? am i going to pee on him? or am i just gonna have an orgasm? help!