In the parent bedroom, the whole family is accommodated in a large bed. A father licks his daughter's pussy while his wife sucks his son's boner while he .
First, the stepmother fucks her stepson, and when they're lying in bed, his father and her daughter get there and the four of them fuck in bed. - Bubbaporn.
both parent sex and child sex contribute so that relationships in the four dyads of mother–son, mother–daughter, father–son, and father–daughter are distinct.