dancing parts?!

So I'm putting Tyler's diaper on for his nap and he proceeds to grab his penis and say "look Mommy my penis is dancing for you." He's pulling and twisting it and doing all sorts of weird stuff. Honestly, I wasn't so sure what to do, but whether is was appropriate or not I did start laughing (a lot). Then I felt like I shouldn't be encouraging that crazy behavior and had a short 'talk' about private parts and privacy. Still, it was pretty funny and it did make me laugh. I just wonder what made him even think to do that??!! Gotta love little boys!