I wouldn't say they were best Друзья but countless times they have both сказал(-а) they enjoy working with each other, Leighton has even сказал(-а) that Ed is her favourite co звезда as he is so professional and that even she knows that they have amazing chemistry.
Not sure if they're *best-friends*, per say, but they both already said, multiple times, that they're really good Друзья and that they really enjoy working with one another :)
I'm glad that Leighton realizes they have ah-mazing chemistry. . . I don't think that they're best, best friends. But I think that they get along very well.