minha meia-irmã me pega se masturbando, ela me diz que se eu deixá-la me foder, ela não vai contar ao meu marido

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)