School Mistress by Bart Beaver
"This is the story of a woman who can give of money and time and skill. If she gives it in a meaningful, unselfish way, the chances are that she will succeed, will convert some of the boys over to a new way of life. But there is something rotten in her heart. She is not selfless. She is selfish. She sets into motion a plan to help oppressed, poor, boys. The idea is to give the boys skill, working skills; to give the boys self-respect; to give the boys what they lack and then send them out into the world as renewed people, people who can compete, who can hold their own, who can make a new life, free from the slums that spawned them.
But the woman is not solely helping these boys for the boys own good. She is seeking to get -- to get from them -- while pretending to only want to help. The fact that she does help some of the boys is not of importance, truly. The way in which she give is rotten, spoiled, soiled."
This novel contains incest/twincest.