bum your mum 

The act of having buttsex with a mother

"Go bum your mum!"

bum your mum by mmmm yummy yummy cummy cummy September 17, 2019

your mummy's bum cunny 

your mother's arsehole

I was thinking earlier about poking a bit of cat shit into your mummy's bum cunny.

your mummy's bum cunny by tudda dahl October 18, 2008