Her Husband's Friend (1920)

Princeton Hadley feels obligated to pay alimony to Judith, the widow of his deceased friend Billy Westover, due to favors Billy had done for him in the past, even though the law doesn't require it. Billy had lost his fortune and was recently divorced from Judith before his untimely death in an accident. Princeton later meets Judith, unaware of her identity, and falls in love with her.