Watch Haim perform '3AM' live with a cameo from Robert Pattinson.

"3am is the witching hour," say Haim of their latest TV performance - a rendition of '3AM' for Late Night with Seth Meyers, featuring a video cameo from none other than "emotional vampire" Robert Pattinson.

Watch the performance below, which includes an important message at the end...

P.S. Read our recent Haim cover story here.