My Slightly Chubby Wife Is an Alien Lifeform

My wife always says she's a curvy girl. I think she's just the right kind of cute. Then one night, I found an encrypted album on her old phone. It was full of photos from when she was thin, her eyes gloomy and her wrists wrapped in bandages. The newest photo was taken on our wedding day: she was crying at the mirror, clutching antidepressants. Just as I was about to keep looking, a message suddenly appeared on the screen: “Warning: Patient's weight is below the critical threshold. Life-support System activated.” Footsteps sounded behind me. She asked softly, “What are you looking at?” I hurriedly locked the screen, but she only smiled. “Looks like it's time to tell you the truth...” “I'm not human at all.”