I know of plenty of couples who turn up together but only perform as individuals, and no one has ever confused them as a duo because their behaviour makes it quite clear they are not. From how you've described some of your behaviour (such as joining in with your husband) it may have given the impression that you are a duo, at least part of the time. To change this not only do you need to explain it to the organiser but you probably also need to reinforce it by performing your solo spots entirely independently without joining in with each other.