So I've had a crush on a teacher (cliché, I know) since the beginning of the 2017 school year. We used to chat a lot, pick at each other, and he'd give me advice about my chosen field. People could tell I was into him, and I got a vibe that he was into me (and my vibes are very rarely wrong). But then someone made a joke about us being like an old married couple and his behavior changed. He doesn't sit with me and my friend at lunch anymore, and if I send him a message on Facebook he won't answer- and I very rarely send him things that are not about class. Is he into me and just being careful so he doesn't get into trouble, or was my vibe completely wrong?