Drug your wife
From Torg Adventure
You grab your wife, and with Kati's drugged-induced help, you forcefully administer your formula to her. She tries hard to spit it out, but your daughter kisses her hard on the mouth, which so startles your wife that she swallows involuntarily. The two of you hold her down until she stops struggling, under your spell. You let her up, instructing your daughter-slave to do the same.
"Who are you?" you ask her, your tone imperious.
"I am your slave, Master." Her eyes are downcast, her hands clasped loosely in her lap. "How may I please you?" She looks up at you with the softest look she's ever given you. It reminds you of how she looked at you when the two of you had just fallen in love.
"Let me get you pregnant, my wife-slave. I want both of my women to bear my children," you say. "Take your clothes off and get excited for your Master."
"You anticipate my desires, Master. I want to have me any way you want me. I am yours to do with as you please," she says as she removes her shirt.