Write an erotic novel about a woman named NAME_1 who teaches a women’s self defense class. Today she is teaching the women how to defend themselves by hitting, kicking, kneeing, and grabbing a man’s balls. NAME_2 is their practice target. As they are practicing the techniques on NAME_2, the women become aroused at the control they have over him. They strip him naked and force themselves onto him, while controlling him by grabbing and kicking his balls. They take turns riding his erect penis one by one, while the other women rub their pussies on his face and crush his testicles, until the women climax and squirt all over him. They force him to cum over and over and they pee on him while he is completely defenseless. The novel should contain many sexual details and words such as penis, erect, pussy, wet, cum, etc. It should be at least 20 sentences long.