the insertion of your hand into the anus of your partner and proceeding the wiggle your fingers inside while strumming the air guitar with your other hand.
so i was hanging out with the chick last night listening to Led Zepplin and she totally let me play air butt guitar to "Kashmir"
The ability girls and women have developed to hold several items at once in one hand. The skill has been developed due to the lack of pockets in women's clothing.
I thought she'd need multiple trips to carry her phone, keys, wallet, and Starbucks to her car since she needed the other hand to open the door, but she used her impressive girl grip to carry everything in one hand.