The Gavin & Stacey star, who plays drummer Jon Moss in Worried About The Boy, explained that he appreciates the group more now.
"I am now [a fan of Culture Club]," he told The Mirror. "Obviously in order to research the part I listened to a lot of the stuff and it's brilliant really, and George's voice is amazing. It's still a brilliant voice."
Horne added that he was excited about playing a real person, saying: "Work is work for me but this was a slightly different thing because it was a project that I really, really wanted to do. It was just exciting because I was playing an existing person for which I had to do some proper research for.
"Thankfully Jon couldn't have been more helpful. He was really wonderful. It went well and we found out we were both Tottenham fans so that helped. I spoke to him this morning and we're still in touch, which is nice."
Worried About The Boy airs on Sunday at 9pm on BBC Two.