Staying erect after cumming???

Sarah • "Eat like you love yourself. Move like you love yourself. Speak like you love yourself. Act like you love yourself." - Tara Stiles 10.1.14💚
I have heard, from friends and online, that after a man cums he becomes flacid and the sex is over. At least for a couple minutes while the guy collects himself. But for my boyfriend that isn't the case. He normally finishes pretty fast, about 10 minutes in. So he will pull out of me, cum, and immediately go back inside me and proceed until I finish. And sometimes he'll even cum a second time. Anyone else have experiences where the guy stays hard and can keep going right after finishing? Or the other way around and gets frustrated by him finishing and not being able to continue?