Muscle Juice

Fischer dumped out his huge jar (Costco-sized pickle jar) of little Lego's onto the family room floor and began to play. I took this opportunity to check my email (not more than 8 feet away). Next thing I knew Fischer sets the "empty" pickle jar on the table next to me... but it wasn't empty. It contained a liquid.

Fischer: "Here Mom, here is some muscle juice for ya."

Me: (Staring... thinking about whether or not he'd had a cup of apple juice... realizing we don't have apple juice...) "Um, what is in the jar?"

Fischer: "Muscle juice"

Me: "You need to tell me what is really in the jar." (and please don't let it be what I think it is)

Fischer: (silence)

Me: "Fischer, what is in this jar?"

Fischer: "Shhh, I'm thinking!"

Me: (bug-eyed) "What is in the jar?"

Fischer: "It starts with a puh puh puh P."

Me: (secretly proud that he knows his letter sounds... freaking out that it is indeed what I was dreading) Calmly, "You peed in the jar?"

Well, this goes into a discussion about whether or not this was a good thing to do or a naughty thing to do, where pee is supposed to go, and what should happen next. He agreed that it was naughty but thought the consequence should be to "just keep playing".
As he was walking to his bedroom for time-out, he wanted me to promise not to wash it out until he came back. ??? After time-out we poured it in the toilet and he washed his hands. Then he says:

Fischer: "Can I have a potty treat now?"
(See, I reinstated the potty treats because he stopped initiating having to go to the bathroom and was waiting till I noticed him dancing around and forced him to go. So, he gets a potty treat if he thinks of it on his own, goes potty and washes up all without me having to tell him to.)

Me: "NO! Are you kidding me?"

Fischer: "Well, I thought of it all by myself!"

Afterthought:
Me: "Did any pee get on the carpet?
Fischer: "No, (beaming with pride) I just stuck my penis in and filled it right up!"