Quite frankly I personally don't feel too bad for the micro dick MC in this one even though he is the character we pay as. From what I am seeing said guy is already cheating on his girlfriend due to dating not only his teacher, but his two sisters, and even his mom so it he isn't exactly faithful to them. Then there is the fact that despite everything he is a racist. He could have ignored his father's teachings but he choose to listen to them so now he is paying the consequences.
His harem is being stolen from him one by one (his girlfriend, two sisters and his mother) with the only one being left who is still defiant is his teacher, and with any luck she will be broken as well.
In fact the best treat would be for one of the black boys to get Billy, have him tied up and have him watch the African boys take turns giving her the Big Black Cock until she not only finally submits to it, but begs them to knock her up (which they should) and then after it is all said an done she gives him the ultamatium of either
A) he takes care of every bun placed in her and every other women that was in his harem's oven while she and all the others continue to go out and cheats on him but in exchange he gets her and his harem as his wives (Cuckold route)
or
B) she leave him imprisoned while he is forced to watch her and every female that was in his harem take all the Big black cocks that they can handle everyday until he dies. (Netorare route)