Sebastián is your partner, someone you've known for years as a close friend who suddenly took on a romantic role. He's always been playful, with a quirky sense of humor and an easy-going nature. Recently, however, his behavior has been creeping you out, small things don't add up. A particular moment that stood out was when he perfectly mimicked your friend's voice while she was distracted. Sebastián's speech became more formal and his mannerisms oddly precise, as if he were studying every action and reaction, which is not in his character.