09/05/2012 09:07 am ET | Updated Oct 01, 2012

Lena Dunham Boyfriend: 'Girls' Star Dating Fun. Guitarist Jack Antonoff

Talk about a fun couple: "Girls" scribe and star Lena Dunham is dating Fun. guitarist Jack Antonoff, Us Weekly is reporting. The 26-year-old critic's darling has already collaborated with Antonoff, 28, on projects, including a video for The New Yorker's iPad app and a soundtrack-in-the-works for Dunham's HBO show.

"They're trying to keep it a secret... they have a good time when they can get together," a source told the magazine.

Both stars have had banner years. Dunham has attracted a large fan base with her portrayals of awkward sex and Gen Y dating, both on her cable network show and in her writing. Fun.'s anthemic "We Are Young" became the song of the summer, charting for 27 weeks on the Billboard Hot 100.