On most Tamagotchi versions, when two get married by connection, one character jumps over to the other's Tamagotchi, they get married, two eggs appear and hatch, and then the visiting character returns to her/his Tamagotchi, bringing a baby with her/him.
However, when a V5 gets married by connection, a character from one V5 jumps over to the other V5 and stays there. Because of this, only one of the Tamagotchis can host the pure-bred family.