Q: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Chris Brown wishes ex Rihanna a happy birthday on Twitter amid rumors of music collaboration Singer answers 'Thanks!' as rumors fly that the two may be seeing each other again 
  
 Rihanna's fans showed an outpouring of love and well wishes on her birthday Monday, but the singer — and the rest of the world — took notice of one message in particular. 
  
 "HAPPY BIRTHDAY ROBYN!" her ex Chris Brown, 22, tweeted early Monday morning, to which the singer, whose real name is Robyn Rihanna Fenty, replied with a quick "Thanks!" 
  
 Rihanna turns 24 this year. 
  
 The "We Found Love" singer's fans quickly posted responses of disbelief and disapproval, with "OMG" and "WTF" comments flying around the Web. 
  
 The musical pair, who split in 2009 after Brown assaulted Rihanna during a dispute the night before the Grammys, have been recently rumored to have reconciled. 
  
 According to Vibe.com, Brown may appear as a guest vocalist on Rihanna's "Birthday Cake (Remix)." 
  
 The two last collaborated on the hit "Cinderella (Umbrella Remix)" while they were still dating. 
  
 Rumors have also been swirling that the two have been seeing each other in more than just the professional sense — with sources telling Us Weekly that "Rihanna loves to live dangerously and talking to and hooking up with Chris is all part of that." 
  
 At the time, Brown's rep denied the reports, saying that the two were "just friends." 
  
 Brown is currently dating model Karrueche Tran, 23, and the pair are reportedly happy together, despite the fact that Brown and Rihanna still tweet loving messages at one another. 
  
 "Karrueche thinks Chris' studio is where most of the hookups have taken place," a source told Us Weekly back in January, though another source added that Brown's new girl "won't give him up for a few discretions." 
  
 jchen@nydailynews.com |||||  
  
  
  
  
  
 Miranda Lambert and Chris Brown have been battling in a public Twitter feud since the Grammy Awards last Sunday night. 
  
 On Monday, country singer Lambert, who is married to "The Voice" co-host Blake Shelton, tweeted: "And Chris Brown Twice? I don't get it. He beat on a girl…Not cool that we act like that didn't happen" 
  
 In 2009, Brown pleaded guilty for assaulting former girlfriend Rihanna and is now serving five years of probation. 
  
 Brown was applauded by the Grammy audience, which included Rihanna, for his performance and win for best R&B; album. His performance resulted in some very disturbing tweets from fans, including things like, "I'd let Chris Brown beat me up." 
  
 Brown responded to Miranda's tweet with one he has since taken down saying, "Hate all you want because I got a grammy now! That's the ultimate f*** off." 
  
 On Wednesday Lambert tweeted back, "I'm done for now. But not for good:) nite love bugs & remember… Be who you are an stand for what u believe in. NO MATTER WHAT!" later adding, "Oh and one more thing for all who are asking….I have a Grammy too:)" 
  
 In a concert Thursday night at the Amherst, Mass., Mullins Center, Lambert held up a handwritten poster that read, "Take notes Chris Brown" and said, "Listen, I just need to speak my mind. Where I come from, beating up on a women is never OK." 
  
 After the crowd applauded, she added, "So that's why my daddy taught me early on in life how to use a shotgun." 
  
 She then sang her hit song "Gunpowder and Lead," which is about a woman preparing to shoot her abusive husband: "I'm goin' home, gonna load my shotgun/ Wait by the door and light a cigarette/He wants a fight well now he's got one/He ain't seen me crazy yet." 
  
 Many of Lambert's songs, like "White Liar" and "I Wanna Die" are known to bash men. 
  
 In three separate tweets yesterday, Brown fired back, "Using my name to get publicity? I love it! Perform your heart out! Go buy @miranda_lambert! So motivational and "PERFECT." Goodnight to all the people who live life and who aren't stuck in the past!" 
  
 Lambert has yet to respond to Brown's tweets but Jack Osbourne, Michelle Branch and Eric Stonestreet have also expressed their disappointment in Brown's Grammy acceptance. ||||| Chris Brown Wishes Rihanna a "Happy Birthday" 
  
 Amicable exes, indeed! 
  
 Three years after Chris Brown infamously assaulted then-girlfriend Rihanna (real name Robyn Fenty), the Grammy winner continues to fuel hookup rumors, publicly reaching out to her via Twitter. 
  
 PHOTOS: Rihanna and Chris' controversial romance 
  
 "HAPPY BIRTHDAY ROBYN!" Brown, 23, tweeted early Monday -- the day the "We Found Love" singer turned 24. 
  
 Hours later Rihanna responded: "Thanks!" 
  
 PHOTOS: Rihanna's hair evolution 
  
 Although Brown is currently dating aspiring model, Karrueche Tran, multiple sources confirm to Us Weekly that he and Rihanna have been secretly hooking up over the past year. 
  
 "Rihanna loves to live dangerously," says a pal of the Barbados beauty. "Talking to and hooking up with Chris is all part of that." 
  
 PHOTOS: Rihanna's edgy style 
  
 A rep for Brown insists to Us: "He and Rihanna are just friends." |||||
A:
Are Chris Brown and Rihanna getting cringingly close? Evidence is mounting that the relationship between the ex-lovers is percolating. Brown tweeted a happy birthday to Rihanna yesterday (in the wake of possible love tweets late last year), and Rihanna responded, triggering a tidal wave of OMGs and WTFs from startled fans, notes the New York Daily News. The two have also collaborated on not one but two new songs. The on-probation singer gushes: "I miss your body" on Rihanna's "Birthday Cake," and adds that he wants to do something with his missing Lady Love that does not involve punching (Rihanna's also featured on a new remix of Brown's "Turn Up the Music."). Rihanna and Brown have been into some sizzling extracurricular activities, sources tell Us, even though he has (another) girlfriend. "Rihanna loves to live dangerously and talking to and hooking up with Chris is all part of that," said one. One singer not about to forgive Brown for his 2009 assault on Rihanna is Miranda Lambert, reports Good Morning America. She's keeping up her criticism with a new tweet, noting: "I don't get it. He beat on a girl." Check out Brown's (NSFW) contribution to Rihanna's song in the gallery, or listen to Rihanna on Brown's remix at the Huffington Post.