Translation:Mommy, don't tell me that terrible story!
I am in the UK. I call her Mum, and I always have. Mummy is what children say, although I've noticed that people in the higher ranks of the middle classes and above tend to say Mummy all their lives. My husband and my father, who both come from the same region, say Mom, not Mum.
Oh no, I've broken Duolingo! After it refusing the words Mum and Mummy, and me feeling more like it's trying to train me to be an American English speaker than an Esperantist, it's got itself stuck in a loop, and won't even accept it's own "correct" answer.
It really rubs me up the wrong way when Duolingo won't accept English (the clue's in the name) English!
If the telegraph had been delayed another 100 years or so, we wouldn't have this problem. American English and British English were already drifting apart before the Revolutionary War. We'd probably still be able to understand each other like the Germans and the Dutch, but we'd be considered separate languages.