The 48 year-old actor was very annoyed with the pop star for allegedly refusing to meet his fiancé when they were all eating at the same restaurant.
Charlie Sheen is known for taking to Twitter to air any grievances or verbally attack another individual, but the 48 year-old's latest target is quite surprising.
"So, I took my gal out to dinner last night with her best friends for her Bday. We heard Rihanna was present as well," the former 'Two and a Half Men' star wrote.
"I sent a request over to her table to introduce my fiancee Scotty to her, as she is a huge fan. (Personally I couldn't pick her out of a lineup at gunpoint)," he added.
Sheen continued: "Well, the word we received back was that there were too many paps outside and it just wasn't possible at this time. At this time? AT THIS TIME?? Lemme guess, we're to reschedule another random 11 million to 1 encounter with her some other night...?"
The 'Anger Management' noted that he had no desire to see the 26 year-old pop star, but his future wife was extremely disappointed she didn't get the chance to meet her.
"No biggie for me; it would have been 84 interminable seconds of chugging Draino and 'please kill me now' that I'd never get back," he wrote. "My Gal, however, was NOT OK with it. Nice impression you left behind, Bday or not. Sorry we're not KOOL enough to warrant a blessing from the Princess. (Or in this case the Village idiot.)"
He didn't stop there either, after Charlie claimed to "always" make time for fans, he targeted RiRi's new bring pink wig.
"Halloween isn't for a while. But good on you for testing out your costume in public," he joked. "See ya on the way down...and actually, it was a pleasure NOT meeting you. Clearly we have NOTHING in common when it comes to respect for those who've gone before you. I'm guessing you needed those precious 84 seconds to situate that bad wig before you left the restaurant."
Sheen targeted Rihanna's new pink wig
"Here's a tip from a real vet of this terrain," he concluded. "If ya don't wanna get bothered DON'T LEAVE YOUR HOUSE! And if this 'Prison of Fame' is soooooo unnerving and difficult, then QUIT, junior!"
The 'Diamonds' singer's reaction was pretty funny! Rihanna changed her Twitter banner to a photo of herself signing an autograph for a fan with Sheen's head superimposed onto the fan's body. She also tweeted, "If that old queen don't get ha diapers out of a bunch..."