Gmail ignores punctuation in its email address. So mail to aero-belly@gmail arrives in the same inbox as aero.belly, aero=belly and so on. It does allow the same name with no punctuation at all, eg aerobelly@gmail in this case (tested this evening). If there is duplication it may well have come from their recent merge of googlemail (UK only
AFAIK) and the main gmail system. Contact support is my advice too.