6x21 - Everybody Loves Raymond

Marie gets upset when she sees Ray calling Lois, Debra's mother, mom so Ray tells Debra that maybe she should start calling Marie mom. When Debra calls Marie mom in front of Lois, Lois gets upset because she doesn't think that Debra should be calling Marie mom since she isn't her mother. An argument between Marie and Lois erupts and they decide that perhaps it would be best if Ray and Debra only call their respective mothers mom.