If I have to continue to work with them for some reason, I confront it directly. In some cases, I have kept notes and documented their behaviors when it's a work environment and their behavior harms the workplace.
In my family, I do something similar for manipulation and deception, though this is not always the right thing to do. Children, teens in particular, seem to go through a stage like this. I don't intervene but will make occasional observations, I will directly state what I think they're doing, and I will set firm boundaries and explain that my reason is that I don't like feeling manipulated. (Sometimes ignoring the behavior can be better, but I just don't have it in me to do that.)
If it's another adult in my personal sphere - a friend or partner - I will give them one chance to correct it. If it happens again and they still pretend to be naive, I stop interacting with them to a degree that lets them play those kinds of games with me, even if it means losing a relationship. I'm a firm believer that whatever I tolerate trains them on how to treat me.