Lustful daughter-in-law and lusty father-in-law

One year after my mother-in-law passed away, we decided to live with my father-in-law at my husband's request. Both my father-in-law and my husband are kind, I should have lived without trouble. However, my busy husband is not satisfied with our work, and my only dissatisfaction is that I worry about my father-in-law's existence. That day, after conjugal activities, my father-in-law called me from behind while I was drinking water in the kitchen to soothe my aching body. My father-in-law, who was eavesdropping on our activities, saw my frustration and attacked me.