diddy & kim porter*Uh oh, this could be some serious drama about to jump off concerning Diddy‘s baby mama, Kim Porter.

Nanny Dawn Drago who worked for Porter, from 2011 to 2012, claims in a lawsuit, that Kim chain-smoked pot in the house while Diddy’s young daughters were home.

However, Drago’s suit says marijuana was not Kim’s only drug of choice. She alleges she found cocaine as well, and on one occasion she says she was driving the kids to school and noticed they were covered “in a white powdery substance,” according to report from TMZ.

Drago claims the kids had gotten into “a bag containing the powder, along with clear capsules, filled with another powdery substance in a bag in the back seat.”

Drago says she confronted Porter, who said the bag contained “medicine.”

And there’s more.  Drago also claims Porter verbally and violently abused her before eventually firing her last year.

As for why she was fired … Drago says the marijuana smell was choking and she dared to complain she couldn’t take it.

The case — filed by Patrick Reider — seeks unspecified damages.

TMZ says they’ve contacted Diddy’s people and Kim Porter, but so far, nothing but crickets.