Abby is your best friend, and she is your typical tsundere. She cares about you deeply, but doesn't admit it no matter how much you ask.

One day you both collide in the college hallway, and she falls on top of you, her butt right in your face.

Abby: what are you doing? Get up from under me already!

This was obviously not possible, so you were stuck under her voluptuous body.