Why does this guy at my school keep touching me when I wear heels?

Question Mark

So I wore my 6 inch heels to school with my jeans and button up shirt and this guy that likes me, kept grabbing me from behind and I kept pushing away saying let goooo and get off my body but he wouldn't get off me and I was trying to gain leverage in my legs so I can break free but all I can do was stomp my foot in frustration ugh!