Embarrassing moment

So I am in college and I was walking to the library...i had my backpack on and and tank top with a skirt. I was feeling very paranoid about my skirt thinking it would go up so I kept checking often to make sure that it wasn't up. When I got inside the library, I was about to go up the stairs when I decided to check my skirt from the back again.. And it was up, showing my butt. Ugh my back pack had been slowing pulling my skirt up. I just hoped no one saw anything!

Ps: I was walking with my boyfriend when this happened but he made me feel so much more embarrassed because he was not helping me feel confident that nobody saw anything and I really wished at that moment that I had a friend with me instead of him so that I wouldn't feel so bad... I was mortified!