Chiho Rukawa - If He's Not Fucking You, I Will, But Don't Get a Divorce!

I'm her stepson, not her husband! Then why does she keep asking for my help whenever she is horny?! When she called me today, she was naked and masturbating with a dildo. I know that my dad is not fucking her as he should, and she makes me hard, but would this be wrong? All that I can think about is how worried I am about her leaving us. If filling her pussy when her husband doesn't is what it takes, then I'll do it. If she sucks my cock as desperately as I think she will, then we both win.