The term for how much of an impact you have on your parent's lives and money. Most poignant when living with parents at an age where you really should have moved out by now.
Derived from 'Carbon Footprint'
Guy 1: "Man, I can't believe you had to move back in with your parents"
Guy 2: "Yeah it's not so bad though, I have a well paid job and I cook my own meals so my parental footprint is pretty small"