The 35-year-old actor portrays sex addict Brandon in the movie - which also stars Carey Mulligan - and he admits he was surprised his penis gained as much attention as it did as there were bigger issues in the film.
He said: "I always liked Brandon - I felt for him. But I knew I had to go to some ugly places with him and he was going to look ugly.
"My nakedness is the easiest part of the film. But yeah, I certainly didn't think, 'Hey, this is going to be titillation city here.' "
Despite becoming a recognizable actor after starring in movies such as 'X-Men: First Class' and 'A Dangerous Method', Michael - who is dating his 'Shame' co-star Nicole Beharie - Michael still tries to keep a low-profile in his hometown London.
He told Shortlist magazine: "I still want to live my life as I've lived it. I try to carry on as is, so it's still pretty much the same thing.
"I came to London for drama school and that'll be 16 years this September."