The Lego Movie star and 28-year-old Vandenberg made their red carpet debut as a couple at a Golden Globes afterparty in January (15), but multiple sources tell Us Weekly their romance has since fizzled out.

The insider adds, "They're still friendly. It was never really serious."

Arnett, 45, was previously linked to Billy Joel's ex-wife, celebrity chef Katie Lee, following his marriage split from comedienne Amy Poehler, the mother of his two sons, in 2012.

Poehler has since moved on, and has been dating comedian Nick Kroll since 2013.