The 'Burn' hitmaker turned 27 on Monday (30.12.13) last week and celebrated at private members' club Shoreditch House, East London where she arrived at 7pm with six friends.
Ellie was left red faced when a pal began taking pictures only to allegedly be told off since many of these kinds of venues have a no-photos policy to protect the stars which visit them, but the blonde beauty made the best of situation and was "really polite and sweet" when addressing staff about the mistake.
A source told the Daily Mirror newspaper: "It was a hairy moment when the staff swooped and Ellie looked really embarrassed as she'd been minding her own business and having a good night.
"She dealt with the faux pas well and was really polite and sweet with the staff, successfully convincing them it had all been an innocent mistake. But the gang left soon afterwards, at around 10pm, as the scene rather killed the party mood."