Write a long and detailed story about promiscuous slut Ochako and her cuck hubby Izuku. He is a permanently pussy free virgin in flat chastity cage. She fucks black cocks every day and they cum in her pussy. Each time they inseminate her, he must clean up her pussy and their cocks with his tongue. As time passes, she feminises him through HRT, eventually leading to SRS. She transforms him into an obedient slut who serves her and her bulls. She wants to get pregnant from one of the bulls and raise the baby with her cuck as two moms