Rihanna and Chris Brown may have spent New Year's Day in bed together and seen the following day driving through Hollywood and stopping at a convenience store at a gas station for some food, but that didn't stop his ex-girlfriend Karrueche Tran from hanging out with him on Jan. 6.

Nor did it stop Rihanna to vent her frustration of their sighting to her fans.

The "Diamonds" singer wrote a cryptic tweet on Jan. 7 that causes speculation that she was referring to Tran.

"Bitch don't kill my vibe," she wrote and linked the tweet to an interesting Instagram message.

The Instagram photo attached was a typed letter that read: "There comes a time in life, when you walk away from all the drama and people who create it. Surround yourself with people who make you laugh, forget the bad, and focus on the good. Love the people who treat you right. Pray for the ones who don't. Life is too short to be anything but happy. Falling down is part of life, getting back up is living."

According to an insider, the 24-year-old pop singer didn't need to feel insecure about Chris taking Tran with him to the Agenda Trade Show in Long Beach, California where he was spotted with her. A source close to Brown said he told Rihanna ahead of time that he would hang out with her.

"Chris already told Rihanna homegirl was going to be there, and she was cool," said the source adding, "Ri thinks of it as his charity work."

Brown and Tran were seen attending the Agenda trade show in Long Beach to promote his clothing line Black Pyramid. Their romantic relationship is allegedly over but they are still business partners, as Karrueche is helping him to promote his clothing line and he is also helping her promote her line, The Kill, according to the International Business Times.

On Jan. 5 and Jan. 6 several fans tweeted sightings of Brown and Tran together. The half-Vietnamese model even tweeted that her day spent with Brown was "pretty awesome."

Karrueche later tweeted "Today was pretty awesome. Can't wait for y'all to see!"

Rihanna was in Ireland while the former couple were seen in Long Beach. She arrived in Dublin on Jan. 4 for a "holiday visit," The Irish Independent reported. She checked out of the Merrion hotel on Jan. 6.

Later that night, to Tran's surprise she would end up going to a Hollywood nightclub that Rihanna was already in. According to a report, Tran went to My Studio and left fifteen minutes later, possibly after learning that the pop princess was already there. Tran later tweeted "What a night." 

A source close to Rihanna said that she trusts Brown when it comes to Tran.

"Things between [Rihanna] and Chris are tight and there's no need for her to be mad or insecure," a source told Hollywood Life. "One thing Rihanna has a lot for Chris is trust. They got this. They're on point with their relationship. She knows Chris already told [Karrueche] it's over between them so she's not even tripping."

Tags: Rihanna Chris Brown and Rihanna Karreuche Tran