When your friend asks you where you are, say this,
Friend: Where are you?
You: I'm up in ur mom
Probably the best thing to say when someone says... whatever they say. Look, I use it all the time, but I don't really know what it means. I'm just using my best definition.
What the person says: So many people make ur mom jokes
Comeback: Yeah, people like ur mom.
What the person says: I slept in my new bed.
Comeback: I slept on ur mom