It seems there is some sort of bromance brewing between the guys from Mumford & Sons and Blink 182's Mark Hoppus: A few days ago, Hoppus joined the band on stage to cover the Eurythmics' "Sweet Dreams," and last night (Aug. 23), Hoppus, along with Tom Morello, joined the band again and performed one of his band's staple songs, "What's My Age Again?." Hoppus, like on the album version of the track, took lead vocals, while Morello and Mumford & Sons played backing band. Check out fan-shot footage of the song below.

The performance took place at a private show in Los Angeles, during which Morello also performed a cover of Bruce Springsteen's "Ghost Of Tom Joad," with which he has a strong history: Rage Against the Machine released a cover of the track in 1997, and Morello played guitar on a Springsteen re-recording of the track for his 2013 album High Hopes.

The next stop for Mumford & Sons is at the Reading and Leeds Festivals. Beyond that, check out the rest of their schedule at their website.