A letter has my sistet and I concern

My mom met this guy in 2015. We just moved in with him since times are getting hard. My mom has got 4 or more cars in her name for him to sale. The first day we met him he got into a disagreement with my sisters and my mom seat there. He never clean the house. His kids came over before we got here and one left a coloring book in the room I claimed as mines. In the book a letter from one of his many babies momas. She expresses the pain he brought he. Its seem he left he when he started talking to my mom. Should I tell my mom?