Hodj, was it a picture of your kid in a Halloween costume high fiving someone?
If that was the one, then I think the photoshop was replacing you with a big fat woman bent over as if the kid was about to slap her on the ass. I could be wrong, I have no idea who even did that shoop. I believe there were a couple others with word bubbles, but the nekkid fatty seemed to be the thing that set everyone off.
I agree messing someone's kid's pics is too far. Just sit there and quietly masturbate to them like you have some class and be done with it.
Note this doesn't apply if the kid doesn't belong to anyone on the forum. For instance the "That's Racist" kid. That's perfectly fine and funny as hell. It's sort of like when you joke around with your buddies about how you banged his wife. Once you meet his wife jokes like that hit a little too close to home and need to stop.
