A New York antique shop owner claims that "Weeds" star MARY-LOUISE PARKER threatened to kill him, and also called him a gay slur that rhymes with the word BAG.

And it was all over payment for a purse her friend sold the guy. The dealer says Mary-Louise told him, "Do you want to wake up tomorrow? I'll make one phone call." Then she unleashed the homophobia.

Parker's rep says she did NOT say either of those things, and the guy is just trying to exploit her celebrity status.