Rights of a non-Muslim over a Muslim:

Rights of a non-Muslim over a Muslim: To visit them when they are sick. To help them if they are in need. To condole them if a family member dies. To buy them gifts. To share food with them. To reply to their general greetings. To congratulate them for marriage,etc. However, greeting them for a holiday that celebrates the birth of God is not one of those rights. Simply smile & say the neutral "enjoy your vacation"!