A sur-name most commonly affiliated with one with fantastic looks and somewhat questionable social skills. The latter is most commonly erased by the prior.
A Lavenstein is typically affluent, well-liked, and has an incredible body, but often puts his or her foot in his or her mouth. Also completely excusable by his or her charm and assets.
That chick was such a Lavenstein, I know she insulted me like 15 times, but I couldn't be mad while I was staring at that rack!