Exactly. I guess it could be a win-win for all: Stepdaddy gets easy and freqent access to a young, juicy, tight pussy (and even perhaps a virgin asshole he could give lessons), stepdaughter earns some additional bucks or the latest iPhone just for opening her legs two times per week e.g., and mommy has an always satisfied husband.
Not really a whore, but a kind of broken girl. Things were turning, when Daddy left the family. And in the years afterwards there were many new men in Mommys life. Some of them found as well their way to the daughters bedroom, when Mommy was at work. And so it started ... She got used to be fucked by older guys. It became normal for her, not a big thing any more. Just to blow them and open the legs for half an hour. And being rewarded perhaps with some Bucks or new Nikes ... There were Whites, Blacks, Latnínos, Asians - she is in the meantime very multicultural. Many will follow.