I know its rare, but I can usually cum a second time without stopping after my first orgasm. It happens especially if I am fucking. If I am super horny I will fuck her hard, then pull out. My cock stays hard for about 4 or 5 minutes in general. Then if I slide it back in and keep fucking, I can usually cum a second time without any wait time. It is less cum, but just as intense.
I know its weird, every girl I have ever been with is so confused, but I keep fucking, and the get over the weirdness. Especially if I make them cum again on the second round.