Lil Tay Drops Mama Joke on TMZ Photog, While Her Mom Has to Quit Job

Lil Tay's talking serious smack about mamas -- especially the one who birthed our camera guy -- but her own mother suddenly has employment issues ... due to Tay's antics.

The foul-mouthed 9-year-old rapper strolled into Mastro's Steakhouse in Bev Hills Thursday evening -- with her pal Swaggy the husky -- and when we dared to ask a question about Danielle Bregoli ... she went off.

Sure, bringing up her archenemy probably wasn't the smartest tactic, but damn!

Meanwhile, Tay's outrageous social media video clips might have cost her mother a sweet job with a real estate agency.

Turns out the Mercedes in this vid belongs to her mother's boss, who was pretty pissed it was a prop for the trash-talking kid. Mama Tay reportedly saw the writing on the wall, and quit before she could be fired.