Once again, Kanye West is in the headlines. Only it's not about his highly anticipated album, The Life of Pablo or his new clothing line Yeezy Season 3. It's not even about his famous wife; instead, West is front and center for some controversy involving pop sensation Taylor Swift. Sound a bit familiar? That's probably because Swift and West have had a long and tempestuous professional relationship. Here's the high points and low moments of a rocky and very public dynamic.

In The Beginning

Flash back to 2009, when a young singer named Taylor West is accepting a Video Music Award for her hit song "You Belong With Me." Suddenly Kanye West grabs the microphone, interrupting her--and making history in the process. People may not remember much else about that show, but there are few that will ever forget that bizarre onstage exchange.

Sorry Not Sorry

Hindsight is 20/20, and apparently West felt pretty remorseful for stepping on Taylor Swift's moment. It took a while, but the rapper eventually apologized to the singer. Swift accepted, publicly saying she appreciated his sincerity.

But by 2013, Kanye had changed his tune considerably. In an interview with The New York Times, West stated categorically that he did not believe in apologies or regrets, and his earlier statements were only issued due to peer pressure.

Reunited And It Feels So-So

It seemed all was forgiven (or at least forgotten) in 2015, when the two reunited at the Grammys. They both spoke warmly of the other in press, and Swift even presented West with an award at the VMAs that year. West thanked her for the gesture by sending her flowers; and all was friendship in the musical world.

Lyrical Content

Unfortunately, the peace between Swift and West didn't last. As if the constant title changes weren't enough excitement for West's new album, The Life Of Pablo is already causing controversy: the lyrics from "Famous" concern a certain blond singer. "I feel like me and Taylor might still have sex / I made that bitch famous." Although West insists that Swift gave him her blessings regarding the controversial lyrics, Swift's camp has said otherwise. By all accounts, the pop star has a serious problem with West's new song (and she's not alone, either).

It's anybody's guess who will make the next move in this ongoing exchange, but anyone who was hoping for a collaboration between these two stars any time soon is in for some serious disappointment.