Is it permissible to visit the atheist maternal uncle and eat from his money, especially since the mother holds special affection for him?

It is permissible to visit a disbelieving maternal uncle and eat from his permissible food, as what is forbidden is befriending him, loving him, and relying on him, not merely visiting him and accepting his hospitality, especially if his conversion to Islam is hoped for, or if that brings joy to the mother's heart, or if estrangement is not beneficial. He must be invited to return to Islam.