In the above diagram, two men (1 and 3) marry each other's sisters (2 and 4), a practice referred to as direct exchange marriage. (Note that marriages are indicated by lines joining partners from below rather than by equal signs.) Couple 2 and 3 beget Ego. Couple 1 and 4 have two children, 5 and 6, who assume a compound relationship to Ego. In one direction they are his father's sister's children; in another, they are his mother's brother's children. (Both pathways are indicated in the diagram in yellow.) As such they are related to ego both patrilaterally and matrilaterally and are therefore termed his bilateral cross cousins.