I was giving a presentation on the biggest project of the semester in front of class one evening. I wanted to be comfortable that night so I wore a strectchy skirt and a light top since it was so hot inside the classroom. The skirt was a little loose around the waist area but it wasn't too bad, at least not to where I was worried about it or anything. Well, during my presentation I felt my skirt starting to slide down my legs, and before I could put it a hand on it, my skirt just fell down to my ankles, pulling my panties off with it, and leaving my vagina and my butt crack completely exposed. The whole classroom was just stunned into silence. I was so embarrassed I wish I could have just disappeared.