my guess would be a birkin?? because its very rare to find, almost impossible actually... but where in the world would he have found a birkin?
aww, sounds like your valentine's day will be sweet (even if it is a little late ). I hope it's that croc bbag in your siggy!
Maybe you can narrow down the choices of bags if you take into account what kind of person DB is. Well dressed? Rich? Does he spend a lot of money on himself? Or is he the more frugal type? I think the gift he wants to give you will to a certain degree reflect his own personality.
Regina