The young man, let's just call him Stallion, is pursuing a very special kind of perversion: he is a reproduction rapist! Not that he would force sex with women - sex is always voluntary! (At least mostly at the beginning.) He only looks for married women and makes them children. If condoms are used for contraception, it's easy for him: holes, squeezing semen and fingers, etc. If the women take the pill, it becomes more difficult: blackmail with pictures that he would pass on to the husbands, etc. Interestingly, most women are more likely to risk one pregnancy than taking care of contraception. A circumstance that he has actively exploited since he was sixteen.
Gloria already has two adult sons and actually takes the pill. Hengst had been her lover for a while when he dropped the mask and blackmailed her with compromising photos. After she stopped taking the pill in a controlled manner, he took her every day until she was finally pregnant. Even after that, he continued to serve her, for her pleasure.
Spoilers: The day after the events in the mirrored room, went into the labor and she gave birth to a daughter.
Johanna already has 4 children (three boys and one girl) and doesn't care about contraception. Her husband wants a stall full of children - as long as they are hers. He doesn't insist they're his. He can't satisfy her sexual hunger so he accepts her sex lovers. He knows that her heart belongs only to him.
Mai is a chance acquaintance of Johanna and loves beating. She is single and uses the temperature method for birth control. She is of no interest to Hengst.