This meaning is used for someone who want it to put in your ass, people who most commonly use this term really want it in the ass, the mum part is a way of saying the you have sexual relations with someone mother.
Someone: What are we going to do
You: I'll Put it your ass, like i'll put in your mum
Someone: OMG yess baby
I'll Put it your ass, like i put in your mum
You: I'll Put it your ass, like i'll put in your mum
Someone: OMG yess baby
I'll Put it your ass, like i put in your mum
by Daddybby November 14, 2019
Get the I'll Put it your ass, like i put in your mummug. A lovely looking lass, easy on the eye as they say and takes to Instagram to show off her tings with provocatively shot pics and creative use of camera angles, despite the fact that her parents also have social media accounts and might see this shit. Then the fucking slag has a kid. Unable to keep her legs shut long enough to keep out the majority of Insta-dicks, she is seeded and Insta-fuckboy as expected, fucks off. Kid barely starts to just be able to walk and say "Mum" when it's given it's own social media accounts and it's not before time that the kid having gotten a bit older now has access to pictures of his own mum being a tart. As do his friends. You guess the rest. Drugs, many other Insta-siblings from many other Insta-dads, bullying, depression and eventually suicide. Fuuuuuck.
"Yeah boi! Saw your mum on-"
"Fuck off! I know she can't keep her clothes on!"
Why does my mum have to be a Insta-mum? Thought Karl whilst crying/over-eating/masturbating/self mutilating later that day.
"Insta-mum! Insta-mum! Does she take it in the bum?"
"Hey Karl?"
"What?"
"Can I have a go on your Insta-mum?"
"............."
"Fuck off! I know she can't keep her clothes on!"
Why does my mum have to be a Insta-mum? Thought Karl whilst crying/over-eating/masturbating/self mutilating later that day.
"Insta-mum! Insta-mum! Does she take it in the bum?"
"Hey Karl?"
"What?"
"Can I have a go on your Insta-mum?"
"............."
by incumbent sausage July 16, 2018
Get the Insta-mummug. 
Your mum. The person who gave birth to you. You have a mum even if you are adopted. What did you expect.
by Hsbs April 1, 2019
Get the Mummug. an aesthetic normally used by young rich mums with 1-2 kids and a hot husband who has a nice house and a financial stable job to provide for the family.
by viviennewestwood November 5, 2023
Get the range rover mummug. by Caverace November 11, 2020
Get the ur mummug. 