I was going to tell my dad a joke, but he still hasn't come back with the milk yet.
Milk Run
Explanation
The humor comes from the absurdity of the dad being gone for an extremely long time to get milk, which is a common trope used in jokes to express the absence of a parent figure. The implied time creates an absurd situation.
Mohammed Loves The Twin Towers
impregnate your gf. you get milk and two people to share your jokes. your welcome.