Does the wife have the right to demand her conjugal right to spend the night with her husband, if the husband is married and has children, and his second marriage is secret and undisclosed to his family and first wife, and the husband spends only a few hours daily with the second wife?

A husband must be just between his wives. Whoever is not just will come on the Day of Resurrection with half of his body inclined. If a man marries a virgin, he stays with her for seven days, and he does not have to make these up to the other wives. If he marries a non-virgin, he stays with her for three days, or seven if she desires, and he must make these up to the other wives. The husband in the question erred by leaving his wife on their wedding night and going to his first wife, and by leaving her alone without her share of the nights. He must fear Allah and give her her right, otherwise, she is permitted to seek a divorce.