In 0.16 you could let the (male) friend of the MC fuck his niece after she comes to live with the MC while the MC sits and watches.
You could also let the (male) friend of the MC fuck the MC's younger daughter before the niece comes to live with the MC.
And you could let the MC's wife service the (male) friend in the same scene. Although I'm not sure how far that scene could be taken since I didn't head down that path.
They sort of set the MC as the cuck, but they are as close as I saw play out.