1. Where's that naughty child now? I'm sure he'll be up to no good wherever he is.

2. He certainly looked as if he was up to no good.

3. I always suspected that he was up to no good .

4. She knew that her brother was up to no good but she didn't tell anyone.

5. If you ask me, that husband of hers is up to no good.

6. You must be up to no good.

7. Anyone waiting around on street corners at night must be up to no good.

8. If these defenses sound familiar, your significant other could be up to no good.