They stole a joke from Shaun of the Dead!
When John is trying to tell his mom how bad Woodcock is he says that Woodcock touched him as a kid and the mom just reakts by slamming something in the kitchen desk and stering at him, so he says it was not true. That is ripped right out of Shaun of the dead.
Shaun is trying to tell his mom how bad his step father is and tells her that he used to touch him as a kid, and she gets the same reaction and shaun tells her it was not true.