The-Bill is a sexual position in which one person inserts a fist into the anus and inserts the other fist into the mouth and lifts the other person over their head shouting "THE-BILL!"
When you're drugged, and something happens to your body that you have no memory of, but definitely happened.
"How was your colonoscopy?"
"I don't know, it was The Bill CosbyExperience... I was awake. Then I wasn't. I woke up. Something was in my ass. But I don't know for certain."