Last Friday was Rihanna’s 21st birthday. And while she was having a private party in Los Angeles, Chris Brown was doing his best to win back her heart.

Here’s what’s being reported in the NY Daily News:

“Chris called Rihanna to wish her a happy birthday,” an insider tells us. “He’s absolutely trying to get back into her good graces. He knows he’s very much in the doghouse right now, and is doing everything he can to show her how sorry he is.”…

He [also] sent the “Good Girl Gone Bad” singer a diamond bracelet and necklace, as well as an iPod Touch. Plus, Brown’s mom, Joyce, who is said to adore Rihanna, sent over a bouquet of flowers.

And apparently Chris’ apologies are working. Here’s more:

Rihanna so wanted Chris with her on her big day, but obviously realizes why they can’t be together right now,” our insider says. “But it’s becoming more and more clear that she can’t be without him

We told y’all last week that Rihanna may take him back…