The "You Da One" crooner received a message from her ex-beau via Twitter Sunday, when he acknowledged the newly cemented 24-year-old's birthday for all the world to see.
"HAPPY BIRTHDAY ROBYN!," Brown tweeted to Rihanna, aka Robyn Fenty, who celebrates her birthday today.
Rihanna responded with "Thanks!" and re-tweeted his message.
And while this is one of the first times the duo has addressed each other via Twitter (by name) since Brown's infamous 2009 assault on his then-girlfriend, it certainly is not the first time Brown and Rihanna have made us raise our eyebrows at some interesting conversation on the social networking site.
At the end of last year, Brown posted "Love U more than u know!" on Twitter, and just two minutes later, Rihanna responded with, "I'll always love you #1love."
And that was just the beginning.
In January, the former couple stirred up the speculation pot a bit more when they were spotted at the same West Hollywood nightclub (it later turned out that Brown's girlfriend was in attendance also) and then again just days ago when neither one of them shut down rumors that the "Turn Up the Music " crooner would be making an appearance on Rihanna's soon-to-be released "Cake" remix.
In fact, it looked like they were kinda encouraging it.
"They can say whatever, Ima do whatever...No pain is forever," Rihanna cryptically tweeted Friday morning after the news broke. "YUP! YOU KNOW THIS."
And then it was Brown's turn.
"Let them be mad!!!!" Brown later followed. "We make music. Don't like it, don't listen! Turn up the music remix is coming soon too! Guess who's on it?"
Back in March 2011, after Rihanna allowed a judge to lessen the terms of her restraining order against Brown, she told Rolling Stone, "It doesn't mean we're gonna make up, or even talk again. It just means I didn't want to object to the judge. We don't have to talk again ever in my life. I just didn't want to make it more difficult for him professionally."