My Dress dilemma

I had some money yesterday and I was at walmart so I thought I would buy one of the dresses I had been eyeing for a while now and thats when I ran into my dilemma, all of the dress were way too short, like bend over a little and your whole ass hangs out. WHAT THE HELL!!!! Do you have to be a slut to wear dresses? Why can't any cute dresses be knee length or close to knee length. URRRGGG