Ed Sheeran's friends have come to expect the pop star to stage impromptu wedding performances at their nuptials because he's easily swayed when he's drunk.

The Shape of You hitmaker has turned wedding singer on a number of occasions for his pals as they tie the knot, but Ed admits he doesn't plan the gigs in advance.

"I don't get asked to play the wedding, I just get invited (as a guest) and then it gets to a certain point in the night where I'm a bit hammered (drunk) and then... I'll end up doing it, so that's happened a bunch of times...!," he laughed on U.S. breakfast show Good Morning America.

However, it seems Ed's friends have caught on to the tactic, and now they often happen to have a guitar on hand in case the singer does decide to perform for the bride and groom.

"It's like, 'It's so weird there's a guitar here...'," he smiled.

Ed previously serenaded Irish star Ronan Keating as he wed Australian model Storm Uechtritz in 2015, and hit the stage with rockers Snow Patrol to perform at the nuptials of guitarist Johnny McDaid's sister last year (16).

He was also recruited by Rixton's Jake Roche to sing as the British boyband member proposed to Little Mix star Jesy Nelson in 2015, the same year he played Cupid for Kodaline bassist Jason Boland to pop the question to his girlfriend onstage during a show at Croke Park in Dublin, Ireland.

Ed's frequent appearances during his pals' big romantic moments even inspired Demi Lovato to name Sheeran as her ideal wedding singer back when she was still dating actor Wilmer Valderrama.

She told the BBC in 2015, "I already told Christina Perri that she's playing at my wedding so probably her and I really want Ed Sheeran... and the list could go on and on."