The insertion of a male's foot into a female's vagina while the girl is extremely trashed, whereas the man will then walk around using the female as a shoe
"Man, these shoes never seem to fit!!! I think I will take Mary's offer of giving her a custom shoe size."
"I had sex with you mom last night!!!"
"Oh yeah?!! well i gave that bitch a custom shoe size!"
By Kellsie
Act Your Age, Not Your Shoe Size
Stop behaving immaturely. Said to adults who are acting like overgrown children and to school-age children who are acting like overgrown toddlers.
It's time for you to get serious and stop being silly. Grow up, pal! Act your age, not your shoe size!
By Randee
Wrong Sized Shoe
Referring to messing something up with a funny outcome. Originating form Harry styles singing "it's gotta be you" live on stage and saying "wrong sized shoe" instead of the correct lyrics.