The key sticks in the lock when I turn it, and for a moment I think Marcus changed the locks without telling me. Then it gives, and I'm inside, and the house is quiet. I wasn't supposed to be home until tonight. The conference in Denver ended a day early—budget cuts, they said, but really it was just poorly organized from the start. I texted Marcus from the airport but he didn't respond, which isn't unusual. He's been distant lately. Distracted. When I asked him about it last week, he said work was crushing him, that the merger was eating him alive, and I believed him because I wanted to. I drop my bag by the door and that's when I hear it. A car door closing in the driveway. I move to the window, the one in the upstairs hallway that overlooks the front of the house, and I see Marcus's Tesla parked at an angle, like he was in a hurry. He's standing by the passenger side, and he's not alone. My twin sister Jade steps out. She's wearing a dress I've never seen before—something tight and red that she would wear, not me. Her dark hair falls in waves down her back, the same shade as mine but styled with the kind of attention I stopped giving mine years ago. We're identical in bone structure, in the curve of our jaws and the shape of our eyes, but somewhere along the way we became different people. She's the one who stayed sharp. I'm the one who softened. Marcus reaches for her. Not a casual touch. Not a friendly hand on her arm. He pulls her to him like he's been starving, and she melts into him, her hands sliding up his chest to his neck, and then they're kissing. Not a peck. Not a mistake. His mouth is on hers with a hunger I haven't seen directed at me in over a year. His hands are in her hair, tilting her head back, and she's arching into him like she knows exactly how he likes to be touched. Like she's done this before. Like this is routine. I should look away. I can't. He lifts her—actually lifts her off the ground—and she wraps her legs around his waist, laughing into his mouth, and he carries her toward the front door like they're newlyweds and this is their honeymoon. My honeymoon. The door opens below me. I hear their voices, low and breathless and punctuated by the wet sound of kissing. I hear Jade say something I can't make out, and Marcus laughs—a sound I haven't heard in months—and then I hear the unmistakable sound of bodies hitting furniture. I move without thinking. Down the stairs. Quiet. My hand finds my phone in my pocket and I open the camera app, my fingers shaking so badly I almost drop it. The living room comes into view. Jade is on the couch—the white couch I picked out, the one we sat on three days ago with our friends for our anniversary dinner. Her dress is pushed up around her hips. Marcus is on his knees in front of her, his hands gripping her thighs, and his mouth— My stomach lurches. He told me he didn't do that. When we were dating, when I asked, he said it disgusted him. That he'd tried it once with an ex and hated it. That it wasn't his thing. But he's doing it now. And Jade is gasping, her head thrown back, her hands fisted in his hair, and she's saying his name like it's a prayer. I press record. My hands are steadier now. The shock is crystallizing into something else. Something cold and sharp. Marcus pulls back just long enough to yank his shirt over his head, and Jade sits up, reaching for his belt, and they're moving together like choreography. Like they've done this a hundred times. She pulls him down on top of her and they roll onto the floor—the same floor where I set up a candlelit dinner three nights ago, where we toasted to five years of marriage, where he kissed my forehead and told me I was the best thing that ever happened to him. The rug bunches under them as they move. Jade's dress comes off. Marcus's pants follow. They're naked now, tangled together, and the sounds they're making are obscene. I keep recording. Thirty seconds. A minute. Two. Jade arches her back and cries out, and Marcus groans into her neck, and I watch my husband come inside my sister on the floor of the home we built together. The phone screen goes dark. Storage full. I stare at the little notification like it's written in a language I don't understand. Then I look up, and Jade's eyes meet mine over Marcus's shoulder. She doesn't scream. She smiles.