Is it permissible for a wife to pray behind her husband's maternal uncle without her husband's knowledge, while he is present and angry?

There is no harm in a woman praying behind a man who is a stranger to her, as long as it is not in seclusion. If the husband becomes angry merely because of this act, he has no right to do so. The wife should strive to appease him, for the Prophet, peace and blessings be upon him, said: "Shall I not tell you about your women who are among the people of Paradise? The affectionate, the fertile, the one who returns (to her husband), who, when wronged, says: 'Here is my hand in your hand, I will not taste sleep until you are pleased.'"