I’m pretty small, less than 6 inches, my ex girlfriend was a bit big, a bit of a wizard sleeve going on. Anyway on one occasion I managed to fist her.
After we were done she asked me how many fingers did I get in I told her four. She put her hand to her face and said oh my god.
The truth is I got my whole fist in, to my wrist. It started off with flat of my palm while both of us were kneeling and kissing on the bed, she was soaking wet put a finger in, then 2, then 3, I made my 4 fingers narrow and into a cone shape, then my thumb in a cone. She was squirming in ecstasy, when I got my hand in up to my wrist I made a fist inside her, I’ll never forget the amount of fluid that came from her, the bed was drenched.
We never did it again or talked about it,. It’s still one of the best sexual experiences I’ve ever had