So, when I was a kid, I peed on my babysitter's couch while taking a nap, then flipped the couch cushions over and pretended nothing happened.
I see. How many times have you peed on another person's couch?
I did it once at my brother's house one day when I was bored.
Seemingly you have this fetish about peeing on things that don't belong to you. That is pretty bad, use the household lavatory if you feel you have an urge to do that. The babysitter will get in trouble just because you were acting like a baby and hiding what you did on purpose, as well.
Hey, I was young and had to go.
Even if these were accidents, you should take responsibility and tell them what you did. It would at least limit the unsanitary conditions you created.