'Affinity' in the Bible

Solomon made affinity with Pharaoh king of Egypt, and took Pharaoh's daughter, and brought her into the city of David, until he had made an end of building his own house, and the house of Yahweh, and the wall of Jerusalem all around.

Now Jehoshaphat had riches and honor in abundance; and he joined affinity with Ahab.

shall we again break your commandments, and join in affinity with the peoples that do these abominations? Wouldn't you be angry with us until you had consumed us, so that there should be no remnant, nor any to escape?