You can still have chemistry on screen without getting on with the person. But it just makes your job a lot easier if you don't have to gird your loins, if that's not quite the right phrase, every time you're going to do a scene with that person.
“In 1930s mysteries, all sorts of motives were credible which aren't credible today, especially motives of preventing guilty sexual secrets from coming out. Nowadays, people sell their guilty sexual secrets.”