Um, seeing as he went to a strip club last night, he's got some big balls calling out his ex-girlfriend for posting a photo of herself in a bikini!

After Chris confirmed that he had fathered a 9-month-old daughter with a former fling, Karrueche Tran dumped him and headed to Mexico with her gal pals, including Christina Milian, to forget about her relationship woes. Over the last few days the starlet has posted a number of bikini photos on her Instagram, and Chris has been paying attention -- and commenting on the sexy snaps!

On one in which Karrueche poses on a chair at the pool Chris wrote, "Thirst trap 101. Continue to be a lady beautiful…U are perfect…Don't let the Thot form from anger." In case you didn't know, "THOT" is an acronym for "that ho over there." And as far as Chris calling her thirsty, Karrueche did caption the pic, "I'm president of the Itty Bitty Committee #ThirstyTuesday," so it's really more of a backhanded compliment from him...but still! Will these two EVER quit each other?

We smell a reunion coming as soon as she gets back to the States...