"Fifty Shades of Grey" opens in theaters just in time for Valentine's Day and the only thing that's probably hotter than the movie itself are it's two main leads.

Jamie Dornan, 32, and Dakota Johnson, 25, will star as S&M-loving businessman Christian Grey and naive student Anastasia Steele in the upcoming movie adaptation of E.L. James' bestselling novel.

The pair recently opened up about how they prepared for the unorthodox roles they played and the process of acting out erotic fantasies in the latest issue of Glamour UK, in which they grace the cover.

Dornan confessed that he often felt "protective" towards Johnson during the filming.

"There were times when Dakota was not wearing much, and I had to do stuff to her that I’d never choose to do to a woman," he revealed.

"I felt very protective and aware that it probably wasn’t easy for her to be put in those situations." he added.