The 'Lego House' singer admitted he and his friend were inspired by an episode of the sitcom 'Friends' where four of the show's characters made similar promises so they have decided if they are both unwed when they turn 40, they will marry each other.
Ed, 22, told MTV: “I do have one of those pacts with a friend actually - my next door neighbour but it's [for when we're] 40.
"We got the pact from 'Friends'. We watched 'Friends' and we were like 'oh that sounds like a good idea' but I don't really want to reproduce with you right now."
Ed has been romantically linked to Selena Gomez and Taylor Swift - who he is currently supporting on her 'Red' tour - and recently admitted speculation about him dating the '22' hitmaker made him feel like a "stud".
He said: "My mates believed it. And my mates are texting me being like, 'Is it true?' so I said it wasn't but the fact that people can believe it makes me feel like a bit of a stud, you know?
"I've got to be honest because one of my best friends did date her. I'm not that kind of guy. But the fact that people believed it impressed me a little bit."