Miranda's sex positions make no sense

When she dates the exhibitionist, he goes down on her during their cab ride and what does he do? He lowers his face sideways towards her closed lap. How does that even work? Does he kiss her belly button? Next.

Then when she sleeps with Steve for the first time, her feet are together while his are on the outside. Does she have a dick and does he have a vagina? How do they make it work? I was watching the scene with my very slender friend who is taller than Miranda but weighs less and not even she said the scene made sense.

For a show that is about sex, it sure is unrealistic.