Ketubot 4 - Death in the family of newlyweds
As we mentioned before , if a parent of either the groom of the bride dies, then if postponing the marriage will lead to the loss of the prepared feast, they put the dead aside for a while, make the wedding, and afterwards bury him and observe the seven days of mourning.
This, however, applies only if it is the father of the groom or the mother of the bride who died, but not in the case of any other relative. Why? - In those times, it was customary for the father of the groom to prepare the wedding feast, and for the mother of the bride to provide her with adornments. So there would be no one to assist them otherwise.
In this situation, having consummated the marriage, the husband separates from his wife for the seven days of the wedding and for the following seven days of mourning and sleeps among men. This is because, after all, the groom is a mourner right after burial. A mourner is forbidden to be intimate with his wife. Thus, although externally he observes the seven days of celebration, in private he refrains from intimacy as a mourner. And even sleeping in separate quarters applies only if he was prevented from consummating the marriage - because then he may be overcome by desire and violate the rules - but if he has already been intimate with his wife once, he can be trusted to control himself.
Art: A Wedding Feast by Pieter The Younger Brueghel