Assisted Mating 10

Sensei thought he had everything under control with his little assisted mating harem, but why is Ursula moonlighting in the pleasure district!? She's been missing for weeks, and she needs to get back into class one way or another. Ursula sets up a series of challenges and if Sensei wins, she'll go back. He has never fully satisfied her up to this point, and with her stacking the deck higher, can he overcome the challenge?