She did not think of herself as a jealous person. She had never been the type to check a partner's phone, to scroll through his messages while he was in the shower, to interrogate him about every female name that appeared in his notifications. But something had shifted in her over the past few months. It started small. A photo he posted of a group dinner, and she was not in it. A woman she did not recognize who commented with a string of heart emojis on his post. He did not hide his phone, exactly, but he angled it away from her when he was texting. He said she was imagining things. He said she was being paranoid. He said she should trust him. And she wanted to. But the small signals kept accumulating, and the trust she wanted to feel was being slowly replaced by a quiet, gnawing anxiety she could not shake.