Heres a theory of mine:
With all the sex that Hunter and Drew have had in the past , I cant see them ever using rubbers with the girls so they must have always cummed inside the girls pussies and asses. So what are the chances that both of them have some sort of sex diseases (STI's) and once they fuck (Brenna,Catherine,Ophelia,Lucia,Tiff ect) they have gave them cladymidia or something. Hunter and Drew could turn it around and say that it is Sterling that has the diseases and passed it on to them. This could then coz Ophelia to kick out Sterling out the house. Hunter and Drew knowing that they have won start fucking the girls with Hunter knocking them up.