Although Rihanna and Chris Brown looked like a happy couple at the Grammy's on Sunday, on Valentine's Day at Playhouse Nightclub in Los Angeles, the two completely ignored each other, according to The Daily Mail.

A source told The Daily Mail that Rihanna didn't know Chris had plans to attend the same club.

Rihanna arrived later than Chris -- and when VIP hosts asked her if she would like to sit with her boyfriend, she declined and insisted she wanted to sit somewhere else.

"Rihanna refused to sit with or even near Chris - and when Chris noticed she was there, he made a huge show of rubbing his presence in her face," the source told The Daily Mail. "He promptly ordered three more bottles of ace of spades which came out with in a procession of sparklers and scantily clad cocktail waitresses, causing a spectacle, which he clearly wanted Rihanna to see."

Rihanna and Chris not only arrived at Popular Demand's One-Year Anniversary event separately, but they left at different times, The Daily Mail reported.

Chris got there around midnight, with an entourage of about 20 people. But Rihanna got there about a half hour later, accompanied by her bodyguards.While Chris called it a night around 2:15 a.m., leaving in his Lamborghini, Rihanna stayed until 3 a.m, according to The Daily Mail.

At the Grammy's, the atmosphere was very different, The Daily Mail reported -- the two snuggled up to each other, smiling and laughing. Rihanna also sported a diamond ring on her left finger, leading some to speculate that the two got engaged.

The on-again, off-again couple just recently reconciled, causing Rihanna's former best friend Katy Perry to stop talking to Rihanna, The Daily Mail reported.

Brown, according to The Daily Mail, is still on probation for beating Rihanna in 2009.