Steps star and fellow contestant Faye Tozer has also hinted her dance partner Giovanni Pernice has sparked a romance with former Pussycats Doll singer Ashley Roberts, following rumours they kissed at the programme’s wrap party.
Sugg and Buswell teased they were an item on Sunday – the day after they appeared in the Strictly final – following weeks of speculation.
YouTube star Sugg posted a picture of himself gazing into dancer Buswell’s eyes on Instagram, along with the caption: “I may not have won the glitter ball, but I’ve won something a million times more special.”
Tozer told ITV’s Lorraine that Sugg and Buswell are an item “officially now” and the other Strictly stars had known about their romance for some time.
She said: “We were all kind of hoping. There was nothing on set. They were all very professional, so that’s really lovely.”
Asked about Pernice and Roberts’ rumoured romance, Tozer said: “I mean, literally on the show you’re so busy, you have to concentrate on the dancing. So, whatever happens ...”
Roberts, who was partnered with Pasha Kovalev in the series, was reported to have kissed Strictly professional Pernice openly at the programme’s party on Saturday after the final.
A source said: “They felt they had to keep things quiet during the show, but threw caution to the wind at the party.
“They couldn’t keep their hands off each other – full on snogging and touching in front of everyone.”
Strictly winner Dooley has also spoken about Sugg and Buswell’s budding relationship.
She told Chris Evans on his BBC Radio 2 breakfast show: “I haven’t spoken to Joe, so I don’t know what I’m allowed to say, but Joe is a sweetheart, Dianne is a dream.
“It was a beautiful partnership and we’re all very, very happy, whatever happens.”
Dooley won Strictly with partner Kevin Clifton, fending off competition from fellow finalists Tozer, Sugg and Roberts.