I don't do this in real life, but I sometimes do a fake laugh when I'm playing with Charlie... kind of like Vince Vaughn in Swingers (except much more low key):

I didn't even realize I was doing it, until Charlie started doing it to me!!! Then I stopped doing it, but now it's too late... and Charlie is always adding a fake laugh to something now. YAPW (Yet Another Parenting Win).

Does your little one ever "fake laugh"?