While dropping off my kids at summer camp, I got the call: my 67-year-old mother, Edith—who has Alzheimer’s—was missing. She’d wandered off while in my husband Nate’s care. For three agonizing days, we searched everywhere. When the police finally brought her home, I was overwhelmed with relief—until she pointed at Nate and said, “Arrest him.”

To everyone’s shock, she claimed she had seen Nate with another woman in our bedroom. When she confronted him, he told her she didn’t live there and forced her out of the house—confusing her into wandering away. At first, I doubted her. But the clarity in her eyes said otherwise. Cornered, Nate admitted it. Yes, he’d had a visitor. Yes, he’d lied to my vulnerable mother and let her go out alone to hide his affair. I kicked him out that same day. My mother may have Alzheimer’s, but for that moment, she remembered exactly who he was—and reminded me, too.