Rihanna turned 24 over the holiday weekend, and of course she got tons of shootouts on Twitter, including one from a very infamous ex.

Chris Brown wished Rihanna, or should we say Robyn, a Happy birthday, in all caps.

Riri replied a simple "thanks" but in her defense she retweeted a lot of people.

However, that same day she finally released the rest of the song Birthday Cake that was previewed on her album, and guess who is singing the guy's part…

Yes, Chris Brown. It looks like the two have been able to put the past behind them and move forward professionally.

So much so that she also makes a cameo in one of his songs.

So is this the beginning of a flourishing friendship? Careful Riri, while it may be a boost to Breezy's career, it could end up biting you in the butt.


And up next

Charlie Sheen apologizes to Ashton.

Last week Sheen called into TMZ Live to express his most recent feelings of Two and a Half Men, saying the show and Ashton himself really sucks.

Charlie has since reached out to TMZ to send Ashton a message, admitting he feels really bad for saying Ashton Kutcher sucks.

He drafted a formal response saying, "Dear Ashton. My Bad. I was disrespectful to a man doing his best. Blah Blah Blah, you deserve better.

So do you think Ashton will except that apology? Only time will tell.