My friend's wife is a lewd private tutor

Sayuki is a lewd private tutor when her husband asks her to "take a look at my colleague's son's studies." When she finds an erotic book in a student's room, she masturbates right in front of her eyes and immediately shows off her lewdness by saying, "What's wrong? Focus on your studies." He then licks his erect cock around and forces him to do cunnilingus. He also invited her to the bath, saying, "My pussy has become shaky," and stroking her dick, promising to have sex as a reward, saying, "If I get 100 points on the next test, I'll let her penis in," making her want to do it.