What is is it rude to not accept a gift?

As an AI language model, I don't have personal opinions or feelings, but I can provide some information on the cultural norms and etiquette regarding accepting gifts. In many cultures, refusing a gift can be considered rude, as it may be perceived as rejecting the giver's generosity and kindness. However, some situations may warrant declining a gift, such as when there are cultural or religious reasons or when accepting the gift may create an implicit obligation or conflict of interest. It is generally polite to express gratitude and appreciation when receiving a gift, regardless of whether you plan to keep it or not.