Not yet

Jennifer pulls her fists out of your ass. You feel empty, and you feel yourself gaping. "Actually," she begins, "I'm running an experiment. Look at these," she gestures to the massive ballsac hanging between her legs that is hanging mere inches from the floor. You look, they seem to be hanging a bit lower since she is so hot right now. "No, they don't just seem bigger, they are bigger. That's why I don't want to cum yet. The cum is still expanding my testicles and sac. Kako came here fully charged and you see she only shrinks a little after each cum. I'm still waiting to see what my peak capacity is."

You wonder how big they will get.