Cum-enema.

She doesn't respond verbally, instead opting to push her ass back hard and clench her sphincter tight as she can before resuming the motion. It's too good! You cum like a fire hose up her tight ass. The pressure and warmth within her makes her have another mini-orgasm. You can't tell, of course, but she can. The torrent of semen doesn't stop for almost a minute and when it finally does you can barely stand. You pull out and close your eyes as you feel the tightness slipping off. By the time you open them again, she's already gone.