ko-o (reflexive verb) (formerly) to become blood-brothers; (these days) to become lovers; to have an affair; to have sexual intercourse. neageata kesi aelokin, apotu komatata aokotokec: when they became blood-brothers they drank each other?s blood. kinyek aisud aelo, imina aikatun esilim: do not get involved in casual sexual intercourse, you may acquire HIV/AIDS.