The ruling on one who is invited to a wedding feast on a day he habitually fasts

Question:
A man habitually fasts on Mondays and Thursdays. If he is invited on a Monday—meaning someone makes an appointment with him and says, "On Monday, if Allah wills, you will have lunch at my place"—is it better for him to say, "I am accustomed to fasting," or should he break his fast?

Answer:
No, he should accept the invitation but not eat. He should accept the invitation and excuse himself from the food. If he breaks his fast, there is no harm. The Prophet (peace and blessings be upon him) said: . If he is fasting, he should make du'a for them and say, "Forgive me, I am fasting, and may Allah reward you with good." He goes to them and makes du'a for them. If he breaks his fast, there is no harm.
Q: Is he given the choice between the two?
A: Yes, he is given the choice. And if they insist that he break his fast, that is better.
Q: Meaning: he is the master of his own decision?
A: Yes, but he should respond to them and go to them, then excuse himself, or he should break his fast and eat with them.
Q: Is it better for him to excuse himself to them?
A: If he is insisting on it by that, and he sees that the benefit lies in his breaking his fast to satisfy their feelings, he should break his fast. If it does not harm them and they do not care, whether he breaks his fast or not, he should excuse himself, saying, "Forgive me, I am fasting, and I came and accepted the invitation. Forgive me for returning."