Tales from the Crypt (1989)

S4E9 Split Personality

Stetson, a charming con artist, has a penchant for dating twins. He becomes romantically involved with a pair of sisters and even concocts a scheme to create a twin of his own. After marrying both women, Stetson plots to eliminate them. However, he underestimates the bond between the twins, who are more alike than he realizes.