"I'm versing you" - A celebration of the continuing evolution of English or simply horrendous grammar?

I've recently realized that it's not just my kids who say things like "I'm versing my sister at Mario Kart" instead of "I'm playing against my sister". Urban dictionary seems to be torn on the matter of the correctness of this usage (http://www.urbandictionary.com/define.php?term=versing) Since I'm no longer able to form opinions without the help of the Internet, I pose the question here. Is railing against "versing" just a lost cause that's just going to make me seem like an old curmudgeon, or a valiant attempt to save English?