The 'Green Lantern' co-stars have become close recently after Blake broke up with Leonardo Dicaprio following a five-month romance and pals revealed they are "trying out" a relationship.
A source told US magazine: ""They hugged and then got in a car together. They became good friends on the set [of 'Green Lantern']. Now they're both single and trying it out. They're seeing each other casually."
Blake recently spent a weekend in Boston with Ryan, 35, where they enjoyed a romantic meal at sushi palace O Ya in the Leather District and the pair were reportedly spotted kissing at Boston's South Train Station on October 3.
He said: "Right now I seem to be on a speed-dating mission - at least according to those stories that are going around at the moment. Even my mom is confused. No man is potent enough to be able to go through as many women as that in such a short amount of time like I allegedly have!"