my keeper is the female in the pairings
whups, that was a mistake on my part, i forgot "not."
only the futa is getting pregnant because only the female is cumming. for the female to get pregnant, the futa must orgasm.
because the base chance for pregnancy is only 35% (without the fertile trait,) it generally takes a few attempts to get the keeper pregnant. because only the keeper can orgasm on command, it can take a while to get a successful pregnancy.