It doesn't matter who cums first if his sperm gets in your vag at all you can get pregnant even if it's just pre cum.
at 6:01 PM on Jul. 26, 2009
It really doesn't matter much, but you coming to orgasm first will help bc the muscle spasms created by it will "suck" the sperm up higher. Its not 100%, but studies do show that it helps slightly. Good luck!