Karrueche -- Chris Brown's A Hypocrite ... So Stop the Threats!

Karrueche is done with Chris Brown's possessiveness and his henchman's violent threats ... and she's firing back.

Chris' ex is responding to a threat made by a member of Chris' posse ... a threat directed at Marques Houston, who gave thumbs up to the pic she posted of her amazing body.

The threat was in the form of a photo of 2 guns, with the caption, "Ni**as sho no how to disrespect, I don't care if they not still together."

Karrueche thinks it's time for Chris, and any of his friends, to get over it -- "I'm bored and tried of this situation. I don't get it because I'm single."

She adds, "I thought we have all matured and moved on. Especially since Chris has been seen with multiple women since the breakup. I don't want anything to do with any type of violence or negativity."

Karrueche tells us she and Marques are just friends, nothing more. The two of them just finished filming a movie together.