During a late night chat with housemates Ollie Locke, Luisa Zissman and love-interest Jasmine Waltz, Lee admitted for the first time that he has previously been "experimental" in the bedroom.
He said: "Yeah I've been with a man. Everyone's done experimentational s***.
"I'm a well-travelled person. I've never admitted it anywhere. No-one's bothered to ask."
Lee's bisexual bandmate Duncan then tweeted: "Oi @LeeRyanMusic I though I was the only "bi/gay" one in the band! Lmao #jumpingOnTheBandWagon".
Duncan came out as bisexual back in 2009 and has also referred to himself as "gay" in several interviews, including one last year in which he revealed his struggle with his sexuality. Duncan explained that he'd felt guilty for sleeping with men because of his Catholic religion.
Ryan has stunned devotees by revealing intimate details about his sexual encounters during the height of his fame – alleging he enjoyed group sex sessions with James.
“Me and Duncan had threesomes! We did some crazy s**t with each other. In the past we’ve done some s**t like that. It’s not weird… you just high five each other. I think they call it a spit roast.”
In 2009, James confessed his shocking gay secret and admitted: “I’m bisexual. I’ve been in loving relationships with men as well as women – and I’m not ashamed.”