I'll add - the nastiest, backstabbing person I ever had the misfortune to know was also not particularly intelligent (I'm being generous here) and unattractive and overweight. I worked with this person and she tried her best to make my life hell (and she was junior to me in our workplace). This was after several attempts by me to be friends with her.
My husband said it was plain old jealousy (she perceived me as having certain things she lacked and I guess thought she deserved). I would say that the person that lambikins' mom encountered in that store was of the same type.
Mind you, a couple of the clips we've seen of these "hunks" show less than attractive personalities ("Do you think you're above me?"...."Yes, I do!").