The 21-year-old singer admits he perspires lots during shows, which made for an awkward meeting with the 'Wide Awake' beauty after a gig in Canada.
Speaking to The Sun newspaper, he said: ''I played the set, stormed it, sweated a lot, got off stage and bumped into Katy Perry. I was like, 'All right Katy Perry, how are you?'
''She said, 'I came to your show and I love your album. I was gonna give you a hug, but eeugh!' and went.
''That was my chance ruined because I sweated so much.''
The 'Lego House' hitmaker is making an effort to look his best at the Grammy Awards next month, particularly after GQ magazine voted him the Worst Dressed Man of 2012.
He revealed: ''I'm going to be wearing a very posh suit to the Grammys.
''And if I run into GQ I'm just going to stick it to them. I've got a proper tailored suit made for me.
''If I want to be smart, I can be smart, I just don't really care.''
Ed is nominated for the Song of the Year gong at the US awards ceremony for 'The A Team', and Sir Elton John will join him for a duet on one of the rising star's tracks at the ceremony in Los Angeles on 10 February.