Chris Brown is still checking out Karrueche Tran's Instagram. Credit: Imeh Akpanudosen/Getty Images

Still hung up? Karrueche Tran publicly cut ties with her on-again, off-again boyfriend Chris Brown earlier this month, but the polarizing singer may not be over the model quite yet.

Brown, 25, made no effort to hide his Instagram-stalking of Tran, 26, when he commented on a sexy bikini photo that she posted on Tuesday, March 17. Tran has been sharing shots from her Cancun beach trip with pal Christina Milian, and gained particular attention for a snap of herself sporting a skimpy two-piece.

"I'm president of the Itty Bitty Committee," the stunner captioned the shot. "#ThirstyTuesday." 

In the image, Tran sits on her feet with her butt facing the camera, cheeks exposed. With her long hair in beachy waves, she looks over her shoulder and sticks her tongue out slightly. 

I'm president of the Itty Bitty Committee ???? #ThirstyTuesday

A photo posted by karrueche (@karrueche) on Mar 17, 2015 at 12:18pm PDT

"Thirst trap 101," Brown commented on the photo, calling out what he saw as an attention-seeking stunt and adding a smirking smile emoji. "Continue to be a lady beautiful... U are perfect." 

"Don't let the Thot form from anger," he added, referencing the acronym slang term that stands for "that ho over there."  

The Grammy winner may have been nodding to the bitterness that Tran expressed on March 4, when she tweeted her farewell to Brown in light of the news that he is the father to a 9-month-old baby girl. "Listen. One can only take so much. The best of luck to Chris and his family. No baby drama for me," she wrote at the time, ending their volatile relationship of more than four years.