A furniture-store cleaning woman became flush with anger when a salesman tried to use the bathroom she was scrubbing — so she bashed him with a toilet-tank lid and then called 911, cops said yesterday

Lily Rose Vaughan, 56, was arrested on assault charges for dustup Wednesday at 1 p.m. in Flatbush Xpress Furniture, where she smashed the porcelain lid on Alen Bairamoukov and then bit him on the neck.

“I’ve had a good relationship with her for many years,” said the shocked Bairamoukov, 35. “I never expected anything like this.”

The salesman said he suffers from gastritis, and desperatelyhad to use the bathroom.

“I said, ‘Rosie, I’m dying, please, I have to go inside,’ ” he said. “She said, ‘Go next door!’ ”

The fight escalated and Bairamoukov was left with a cut hand.

Vaughan was arraigned on assault charges and released on her own recognizance. She said she was acting in self defense.