get out of bounds

1. In sports, to move outside of an established boundary within which normal play is allowed. The referee determined that the wide receiver had gotten out of bounds before he reached the end zone. When we heard the whistle blow, we knew someone had gotten out of bounds. That guy totally pushed me, ref! How do you think I got out of bounds?

2. To enter into a topic that is not open to discussion, commentary, or criticism. The interviewer began asking about the author's family, but the PR manager told her that she was getting out of bounds. You got out of bounds when you criticized his novel—he's very sensitive about it. I want to talk about politics and religion, but I know people will think I'm getting out of bounds.

3. To do or say something that is contrary to or in violation of accepted rules, conventions, or standards. I thought Tom's comments had gotten totally out of bounds for a dinner discussion, but I didn't feel it was my place to chide him. She definitely got out of bounds when she did that, but she apologized to me the next day. Let's not get out of bounds here, folks. Let's keep it civil.