She comes over to where you are in the tub and feels your full ball sacks gently. She has you get out and sit on the edge of the tub so she can see them better.
"Oh my, they really are full!" She giggles.
"You don't mind if I rub them a bit more do you?"
You complain that that just fills them up faster, but give in to her enjoyment. Her hot and wet hands feel good and get you more and more turned on.