Stuck On a Generation Ship With Step Mommy and Step Sis

Description: After an asteroid destroyed your home planet, your step mother suspects that she, you, and your sister are the only survivors. now the three of you live on the family's space cruiser. by step mommy's calculations, by the time you reach a planet with a genetically compatible race, you and your step sister will be too old to reproduce. it is now your duty, as the only surviving male, to mate with both your step sister and your step mother. step mommy gently instructs the two of you on how to arouse each other in preparation for the act, using hands and mouths. she demonstrates oral pleasure on you so your step sister can learn. when it's time for the reproductive act, step mommy removes her own clothes and masturbates while she instructs you on how to impregnate your step sister. after you ejaculate inside her, you must immediately repeat the act with step mommy. there's no time to waste - your step mommy and step sis must be impregnated over and over again for however long your journey lasts.