The Irish rugby player, 26, said he believes the star thought he was gay because the private message they sent him on social media was 'pretty flirty'.
Greg, who won the show with former flame Amber Gill in 2019, said on a recent podcast: 'Sam Smith followed me and slid into my DMs.
Spilling the beans! Love Island winner Greg O'Shea has revealed that he believes Sam Smith once tried to chat him up by sliding into his direct messages on InstagramInsurance Loans Mortgage Attorney Credit Lawyer
'I think [they] thought I swung the other way and slid in pretty flirty.
Speaking on the Rig Biz podcast, he continued: 'I was with the rugby lads in Vancouver and was like, 'What do I do? It's Sam Smith, I have to reply! But I think [they] think I'm homosexual.'
'[They] messaged me like, 'Hey, how are you handsome?' with a heart emoji. I just replied saying 'Hey man, what's going on?'.
'[They] gave it a like and then I think he just moved on.'
Flirty: The Irish rugby player, 26, said he believes the star thought he was gay because the private message they sent him on social media was 'pretty flirty'
Greg was selected as a member of Ireland's Rugby sevens players and made the trip to Japan ahead of the start of the games earlier this week.
Sam, who most recently publicly dated Brandon Flynn, came out as non-binary in 2019 and announced that their new pronouns were they/them.
Greg believes he may have upset the Lay Me Down hitmaker by misgenders them, adding: 'I don't think he identifies as a man or a woman, I don't know what he identifies as, but I think me calling him 'him', or saying, 'man' may have put him off.
'I could've played it better!'Insurance Loans Mortgage Attorney Credit Lawyer
Reality star: Greg, who won the show with former flame Amber Gill in 2019 (pictured), said on a recent podcast: 'Sam Smith followed me and slid into my DMs
MailOnline have contacted Sam's reps for comment
Last year, Sam told The Sun they would now be open to dating a person of any gender identity.
Sam said: 'I've never really kind of played by the rule book. I love people and whoever I fall for, that's who I fall for. I don't know who that's going to be.
'Now I don't know what gender they will be, to be quite honest, and that's a freeing thing — to not be limited to one category of person.
'I just fall in love with whoever I fall in love with. I generally have never really thought about people, any human beings,