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 incrediblebody, 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!