get the wrong idea (about someone or something)
To develop a belief or impression (about someone or something) that is untrue, incorrect, or has been misinterpreted or misunderstood. I feel like I need to explain my actions, or you'll end up getting the wrong idea about me. Now don't get the wrong idea or anything, but I think we should spend a little bit of time apart. Whoa, I think you've gotten the wrong idea about tonight—this wasn't supposed to be a date or anything like that!