Doing ur mom
The act of having an intercourse with someone's female parental figure.
"Im doing ur mom"
do ur mom in the ass
where u say a joke about somebody else is mom
hey jim, i did ur mom in the ass the other day
I'm Doing Ur Mom
It's A Goofy Joke/j And It Means Having Sex With Someones Mom.
Billy: Oi Jil I'm Doing Ur Mom Tonight.