Here's a Roger Davis story that appeared in the great book A Hard Act to Follow as well as Barnabas & Company:
A crew member noted that Roger liked to interfere with the lighting and blocking, usually to upstage whatever actress he was working with. He made the mistake of trying this with Grayson Hall during one of their scenes. Grayson ground her heal into Roger's toes as he said his lines. The crew member noted that tears of pain welled up in Roger's eyes. When the director called cut, Grayson learned in and said through gritted teeth: "Now you'll never try that again, will you?"
