Aside from the mitzva to honor and serve our parents, there is another mitzva, called mora, to stand in awe of them – by not sitting in their designated places, by neither contradicting what they say nor expressing one's approval of what they say, and by not calling them by name.
How far does this obligation go? If one is wearing precious garments, is seated at the head of the table in the presence of the entire community, and his father or mother come in and tear off his clothing, slap him and spit in his face, he must not shame them. He should remain silent and fear the King of Kings, Who gave him this command. For if a king of flesh and blood decreed something that would cause him even greater distress, he would not even flinch in protest. How much more so with regard to the decree of ‘the One Who spoke and the world came into being in accordance with His will!’
Although, according to many opinions, the son may demand that his parents reimburse him for the loss, he may nevertheless not shame them for their actions.
Once, during Pesach, the elderly mother of the tzaddik, Sar Shalom of Belz, was sitting next to her son during the seuda. The tzaddik was eating soup while she ate her matza, and because she had no teeth, she kept dipping her matza into his soup. Despite this, Sar Shalom went on eating his soup, even though he was known to be very stringent with gebroks.