It's not just you, that's a pretty common fantasy.
I remember my first session with Annie R., and how she lined us up in front of the mirror, stood in front of me and flexed, and completely obscured me despite me being taller. Of course, she was very happy to position me in a way that immediately let her know how much I enjoyed that. I came to find out that this was almost de rigueur for most of my sessions, and usually just a starting point.
I've never used a tape to measure a sessionette or myself; just my used hands as a rough measure. "Look how small your bicep makes my hands look. WOW." I prefer sessioning with the more muscular women, so they usually easily outclass me in terms of size. I don't think I was able to make a circle around one of Amber D's calves with both hands.
I'm hoping Lisa Cross comes to the East Coast, but between COVID and her planning her new boobs, I don't know if that'll be anytime soon. She's... a brickhouse, and a damn sexy one. I can't wait to get on my knees in front of her.