Admitting a mistake, casually

Meter la pata

meh-TER lah PAH-tah — To mess up / put your foot in it

"Le pregunté por su ex sin saber que habían roto. ¡Metí la pata!"
I asked about her ex without knowing they'd broken up. I put my foot in it!

Literally "to put in the paw/leg" — used specifically for a social blunder or an awkward mistake, not just any error.

"I did this spectacularly once at a family dinner and never lived it down — a story for a lesson sometime."— Graciela