Adam Lambert and Sam Smith did "a lot of bonding" in London.
The 35-year-old singer insists he never dated the 'Stay With Me' hitmaker but thinks he is "so funny."
Asked about speculation he was romancing the British singer, Adam told 'Watch What Happens Live with Andy Cohen': "I love that rumour, actually, the minute I heard it, I texted him and said, 'So?' He's like, such a nice guy, he's so funny [but] no, there's no romantic rumour.
"We did ride a rickshaw in London from one club to another, wasted, at like 3 a.m. in the morning. So, there's a lot of bonding."
Adam previously praised Sam, 24, and Years & Years for raising LGBT awareness through their music and urged record company executives to "come around a bit more to it."
He said at the time: "It'd be nice if there was more ... I think it'll happen slowly but surely. There are success stories happening and that's the biggest thing for the music industry. They need to see that it actually works in order for them to feel comfortable with it. The audiences are there for it, but the industry needs to come around a bit more to it. They are, but it's the last piece.
"Luckily we're in a moment right now with streaming where there's more power put back into the artist's and audience's hands. But the gatekeepers who make a lot of the other big decisions in the music industry, those are the ones hardest to convince on certain things. That's the reasoning for some of that pronoun stuff."