The former Coronation Street actor will play 'greedy' footman Thomas in new costume drama series Downton Abbey.
"It's a dream job because it’s completely the other side of the spectrum, particularly as it carries on," the actor told the Manchester Evening News. "My character gets nastier."
He admitted that it was his idea for Thomas to kiss a visiting Duke, played by Charlie Cox, in the first episode.
"It wasn't actually in the scene but at the second rehearsal it dawned on me that there was a moment missing and we could improve it," he said. "I'm sure my friends back in Manchester will have a few things to say. But you play a character who happens to be gay. It's not an issue."
James-Collier confessed that he had found the kiss easier to film than on-screen embraces with female co-stars.
"When you're kissing a woman and you want it to look realistic, you're thinking, 'Am I taking advantage of her? Is her boyfriend going to think I'm over-stepping the mark?'" he said.
"Whereas when you are kissing a man, those thoughts don't cross your mind. I'm more scared of it looking false, so I went for it fully to make it look real and hopefully I've achieved that."
The 33-year-old added that he is not sure how Coronation Street viewers will react to his new role.
He said: "I don't know if Coronation Street fans will be shocked. I want to show myself in a different light. Before Coronation Street I was a jobbing actor and after it I'm a jobbing actor again. You're in different parts all the time and people have to twig that it's not real."