Could I call adult protective service on my step-grandfather if he is having an affair with my grandmother's caregiver?

My grandmother has Alzheimer and we recently found out that my step-grandfather who is married to my grandmother is having an affair with the caregiver that is taking care of my grandmother. The caregiver isn't contracted by any company. I have screenshots of my step-grandfather posting pictures on his facebook of my grandmother nurse calling her "his love" and calling her family his inlaws and stating he's found his better half, while currently my grandmother is still living and they are still married living in the same house. My grandmother has completely stopped eating and is pretty much skin and bones! We believe the caregiver is now living in my grandmother house and also brought in her little son too. My step-grandfather is keeping us away from seeing my grandmother also, and has also taken us off of every assets my grandmother has promised us when she was in the right state of mind. what can we do If he is having adultery and infidelity and is just waiting for my grandmother to die to take all her assets? We are in Texas. My grandmother stays in a room all day, we're not even sure if she showers. My father tried to speak to my grandmother on the phone today and she didn't want to speak because she said my father hits her. My father than ask my grandmother if someone is hitting her over there and she didn't respond.