Fifty Shades of Grey: How Charlie Hunnam & Dakota Johnson Proved They Were Sexually Compatible

The Wrap reports that the actors had to do a "chemistry read" before any final agreements were made

We have 50 whole reasons as to why Charlie Hunnam is the perfect choice to play the male lead in Fifty Shades of Gray.

And, call it reason No. 51, but if the producers had somehow got the casting of Christian Grey and his sexual protégée, Anastasia Steele, wrong...talk about your flaccid endeavors.

Dakota Johnson's willingness to do full-frontal nudity aside, not every pair of hot actors are automatically fit to be tied (to the hottest project of the year, that is).

In fact, it turns out that Universal Pictures didn't want to take any chances that Hunnam wouldn't mesh with the onscreen object of his affection in the adaptation of E.L. James' best seller, so the pair were required to do a "chemistry read" before any contracts were signed, according to The Wrap.