Lena Dunham and Jack Antonoff Split After 5 Years Together

In December, Lena Dunham and Jack Antonoff quietly ended their relationship of five years.

The couple began dating in 2012, but a source close to them told E! News that they'd been growing apart for quite some time leading up to their split.

"It was mutual," said the tipster. "Jack and Lena were growing apart and it just made sense for them to end their relationship where it was."

"They want the best for each other no matter what," the source added. "They are both moving on."

Dunham — best known for creating HBO's Girls — hasn't been seen at a public event with Antonoff since the Grammy Awards back in February. Antonoff is the frontman of the band Fun. He also performs in Bleachers and Steel Train.

While their romance was reportedly fizzling, Dunham wrote an essay about Antonoff in Variety back in October. Antonoff made the outlet's list of 50 influential New Yorkers, called New Power of New York. In it, Dunham praised Antonoff's passion and positivity, though she didn't fail to mention some of his less savory habits.

"It's easy to forget someone's magic when you've lived with them for half a decade," she wrote. "Their refusal to pick up their towels or get more seltzer or clean the hedgehog cage becomes a narrative louder than, 'They're changing the world with their passion and skill.'" Though most of the tribute was more flattering, those lines stand out now in the wake of their break-up.

Dunham was in the headlines a lot this fall, though she kept her break-up under wraps. The young showrunner took a lot of heat for defending her friend and fellow Girls writer, Murray Miller, against allegations of sexual assault. Dunham, an avowed feminist, accused Miller's alleged victim of lying about the attack, drawing harsh criticism from the burgeoning "Me Too" movement and alienating a large portion of her fan base.