We came from Palestine to Egypt and went to see one of the fathers. He offered us hospitality and we said, “ Why do you not keep the fast when visitors come to see you? In Palestine they keep it.” He replied, “Fasting is always with me but I cannot always have you here. It is useful and necessary to fast but we choose whether we will fast or not. What God commands is perfect love. I receive Christ in you and so I must do everything possible to serve you with love. When I have sent you on your way, then I can continue my rule of fasting. The sons of the bridegroom cannot fast while the bridegroom is with them; when he is taken away from them, then they will fast.”
Taken from Paradise of the Desert Fathers