Your butt — peach, glutes, booty, derrière, whatever you want to call it — is undeniably an asset. There are entire workouts designed to tone it, songs that make you shake it like a Polaroid picture, and jeans and shapewear promising to lift and shape it so baby has back. The truth is: my butt’s always been strong. Back in my competitive days as a teenage tennis player, I was all about footwork, gliding across the court like a petite but mighty gladiator. My nickname, Mikiller. An intimidating fear factor for opponents; a fierce, small warrior princess ready for battle. I remember college, chilling in the dorm with my besties,…