Fuck your college-age sister again

You're about put your cock back in her when she pushes you down.
She straddles your crotch, aims your cock at her opening, and shoves down. At first you feel uncomfortable with her weight on top of you, but she is too good for you to tell her to stop. You cum. She cums. You cum again. So does she. And again. And again.
After you cum in her for the ninth time, both of you are spent.