The two actors reportedly became close after Rob joined the ITV soap playing Ken Barlow’s son last December.
The couple sparked rumours they were an item after attending last week’s British LGBT Awards together.
Now a source has told The Sun: “Daniel was instantly attracted to Rob when he joined the cast.
Rob, who has always been open about his sexuality, admitted recently that he was concerned ‘Corrie’ bosses would match him up with a female character in the soap.
“I never planned to keep it quiet that I was gay,” he said.
“The only concern I had at first was if I’m with a female character, will an audience who knows I’m gay in real life believe it? But that was just my own fears because I do believe they will.”
Daniel has played Corrie’s gay vicar Billy Mayhew since 2004, and appeared on Channel 4’s ‘Celebrity First Dates’; last year in a bid to find romance.
However, despite telling his date that he was on TV “six times a week”, he failed to recognise him.