Facts: A knows that his colleague B is having an extramarital relationship with a female colleague. A points out to B that he would tell B’s wife about this relationship if he did not give him EUR 10,000. B gives the EUR 10,000 to A. When B’s wife finds out about the affair by other means, B wants the money back.

Question: Does A have to pay back the EUR 10,000 he received as a gift?