by billwells1
If there is anything left of interest in this story of yours, it would be to try to understand what went so horribly wrong in the upbringing of Jeff and in his relation to his mother (and perhaps women in general), that he now has an almost sadistic interest in, not only humiliating his mother at the strongest, but also hastily jeopardizing her health by forcing shit bacteria from her ass into her mouth.
This story, as sad as it has become, has nothing to do with erotica anymore, not even with incest as a sexual phenomenon. It's rather just about power, extortion, degrading, humiliation and, hence, most likely psychopathy. That you describe the two adult sisters to enjoy this, could possibly imply a story of family abuse that could, for an author with real insight to the complexities of the human mind, be the basis for some interesting literature.
However, this simplistic and not credible "porn" story (for severly twisted minds, that is), that you now have let your, in some ways skillful, writing sink down to, leaves me cold. It only makes me wonder whether these scribblings just are a not so successful attempt at describing some minds other than the author's own, (that the female voice of the story deviates from the author's own has long been apparent from the repeated ramblings over the almost hypnotic effects of the sight of a large penis), or whether they rather reflect some quite troublesome aspects of the author's own mind.
Regrettably you lost it -- and you lost me.