When you find that another person is trying to manipulate and take advantage of you, take action to protect yourself. If you do not want to directly attack them, it will help to protect yourself from passive methods of manipulation.
The easiest way is to change the topic in another direction. This can be done either with a gradual change of topic, or a sudden change of direction of the conversation, although the second option is a more active method.
The second is the method called autopilot. While your correspondent describes that you have to do something for them, respond on autopilot.
Answers must not indicate anything – things like "good", "interesting" and "that’s nice", thus the arguments of the person will be met by total resistance, without causing you any harm, and they will begin to feel confused.
It is imperative to increase your physical distance, if you want to stop the manipulation of your interlocutor. If you stand back a reasonable distance from them, it helps to reduce their impact on you.
You can also imagine that between you and your companion, there is a filter and what you will receive depends on what and what you wish to accept. All phrases and emotions are under your control, the filter must allow only the information that you may find useful.
Hide their emotions from the person, it is very important, but not easily done. If you feel that someone is pressuring you, do not yield to provocations and hide your emotions. You can pretend that you do not hear a word they say, or simply ignore their arguments.
It helps a lot if you do not say anything to your companion and when it is your turn to answer, and they require you to input, pause about a minute, just to watch their eyes. Then, you can tell them your answer. With this technique you can judge the situation better and choose the correct answer.
To confuse the person, imagine them in a comic situation and smile at the most inopportune moment, when they speak to you about serious things.