Chainsaw Sally (2004)
In one scene, Sally and Ruby both explain to one of their victims that "The Toolbox Murders" is one of their favorite movies.
Ruby and Sally like to reinact horror movies. In one scene, Sally is dressed up like Leatherface chasing Ruby around with a chainsaw while Ruby is dressed up as Sally Hardesty.
After reinacting one of their favorite horror movies, Ruby decides he wants to take a shower and tells Sally that she could play "Norman".