The mystery of the choked toilet

Friday morning the toilet in the master bedroom suddenly got choked. The water was not draining as it should. I looked at my son suspiciously. He looked back like this:

"What? I didn't do anything mama." 

Hmmm, we watch him like a hawk in the bathroom. He has an agenda when in the bathroom. 

Usually, it's to head straight to the toilet and throw the toilet paper next to it into it. He generally pulls it off in pieces, and that is not too bad. 

I had to call the plumber and $250 later found the culprit. 

The number 4 stacking cup, one size smaller than this one was retrieved from the toilet. Hmmm. 

I look at him suspiciously now all the time. Twinkle in his eye, and I'm on my guard.