You try using your mouth.

You open your mouth as wide as possible, and Sandra aims her penis there. After she fills you up, you move around under her, and push her cum into her ass with your mouth. Unfortunately, she isn't able to control her orgasm, and she keeps cumming over your back and ass until you get your mouth to it again. You only manage to get three trips total before she is finished.

"Oh, I don't hardly feel any cum inside of me," she complains. "We need to figure out a better way."