What it means
Means pregnant, usually said in a cheeky, slightly crude way. It’s the kind of phrase you drop with mates down the pub, not in a work email or at the clinic. It can sound rough or a bit dismissive if you’re not close, so use it carefully. Makes baby news sound weirdly casual.
Usage examples
"He rocks up to the pub and goes, Our Jess is up the duff. Baz spits his lager and says, Mate, you’d better start baby-proofing."
"Turns out she was up the duff at the Christmas party, that is why she stuck to the lemonade all night."
"You know why Kelly's gone off pints lately? She's up the duff, mate, keeping it quiet till the scan."
"His mum clocked the morning sickness and just went, Don't tell me she's up the duff already."
"Saw her passing on the prosecco and Dan just leaned in like, Go on then, who's up the duff?"
Where it comes from
Cheeky British and Australian slang for pregnant. The duff is an old word for dough or boiled pudding, so being up the duff plays on the bun-in-the-oven idea, a touch crude but always said with a grin. You will hear it announced at the pub long before anything official, usually with raised eyebrows.
