Other than swearing, because I think all kids have done that. Stuff you aren't supposed to laugh at but do, just because of that phrase your parents say to you when you are young: "I hope you have a child(ren) just like you..." Or something similar. Nathan was attempting to open the patio door to go outside. I warned him not to because he was not dressed (he was still in his diaper and night shirt), and instead of listening to me, he sassed me by sticking his fingers in the corner of his mouth, stuck his tongue out and opened the door quick and dashed outside and I had to chase him. He thought this was oh, so funny of course. I had to hide my laugh with the sassy face he made, because that is the first time I had seen him make that face, and I didn't realize he knew how.