私の義理の妹は私が自慰行為をしているのを捕まえ、私が彼女に私をファックさせれば、彼女は私の夫に言わないと私に言います

My stepsister is in the house where I live with my husband, suddenly she discovers me masturbating because my husband doesn't please me, she tells me what she is going to tell my husband, I ask her to please not do it, then she tells me that I won't tell her if I let her fuck me too (Spanish)