The girlfriend's mother, who came to stay at the cramped house where the couple lived together, became aroused and seduced the boyfriend, resulting in him ejaculating inside her. (Shoda Chisato, VEC-622)

Worried that her daughter had started living with her boyfriend, Chisato suddenly appeared, but the two made no attempt to hide their romantic relationship, making Chisato's heart race. That night, hearing faint moans from next door aggravated Chisato's body aches. Although she knew she shouldn't, the sound of clothes rubbing together only intensified her lust. Finally, reaching her limit, Chisato, in a brief moment between the two sleeping, straddled her daughter's boyfriend and had sex with him while they slept together…