(Devarim 22:22) "If there be found (by witnesses) a man lying with a woman cohabited with by a husband": including one who was cohabited with in her father's house": i.e., while betrothed (and not yet married). Variantly: "cohabited with by a husband": R. Yishmael says: Scripture comes to teach us about a yevamah (a woman awaiting levirate marriage) that one who lives with her is not liable (to the death penalty) until he (the yavam) cohabits with her.