Russian chick in stockings spread her legs erotically

Whatever you say, the most offensive thing in life is when your close and beloved people betray you. So in this situation, my stepsister Diana Ryder takes a photo of me naked and promises to send the photo to my girlfriend. To prevent this from happening, she asks me to fuck her and then everything will remain between us. Well, for me it’s really not a problem, and my sister is much better at shitting than my current beloved. What do you think - is this normal?!