two girls are jealous of a popular girl so they start a rumor that shes a "backseat betty".

I've been jabbed

Britney: Hey Lohan, did you call that guy we met at the coffee house yesterday?
Lohan: Yes, we met for drinks and well sex this morning.
Britney (laughing): Sometimes you can be such a back seat betty.

Nicole: Paris, did that guy give you a ride home from the club last night?
Paris(smiling): Yes, you could say that he gave me a ride last night.
Nicole: Your family should have been in the automobile business, because you are such a back seat betty.

Jan's friends refer to her as back- seat betty because of her many one night stands.

I got all up in that backseat betty i took out last week.