When I showed up at Joan’s on Third the other day to meet my friend Booth for lunch, I had no idea we would be three. But lo and behold, who should join the party but a Louis Vuitton “Neverfull” in Mongram Roses from the Stephen Sprouse Tribute Collection. The bag, which is chic beyond belief and soooo much better in person, did not order a sandwich but rather wistfully watched as we nibbled on tarragon chicken salad and sipped Arnold Palmers. Good luck getting your hands on one of these lunch companions. They sold out about a minute after they were released last Friday.