Callum stars as Colin in the acclaimed drama (Picture: Channel 4)

It’s A Sin star Callum Scott Howells has spoken about his experiences behind the scenes on the show, revealing the hardest scene to film.

The series created and written by Russell T Davies provided viewers with some of the most uplifting and heartbreaking moments on TV over recent years – and it’s no surprise that some of the scenes were as hard to film as they were to watch.