Debauched

My husband wants me to be closer to his sister. Much closer. I have postpartum anxiety and need social support. But the closer I get, the more she pushes me to do things I'm sure would wreck my marriage to her brother. She begins using me as a testing tool for her boyfriends. My husband pushes me to be close to her, but I don't think he understands how far his sister is willing to... debauch me.