Sitting in the middle seat in the back seat of a car. This is a softer, less abrasive way to describe this than using the term "sittin' bitch."
Passenger 1: Car's full, James. Looks like you'll be sittin' ho.
James: Those are the breaks, Passenger 1, but thank you for substituting the term "ho" for the term "bitch." I feel much less emasculated. You are a king among men.