Always take into consideration your need in a situation, but without imposing it. It is always easy to take yourself into consideration, without sacrificing yourself in order to be loved. Sacrificing yourself for the other person, in a way, is to avoid considering yourself. This quickly becomes destructive for the couple. Sacrifice is a poison that kills self-love and love for the other.
When a situation is not right, I have two things to observe before saying yes or no:
First: identify the need. What is it about this situation that doesn't work for me? It is important to be aware of your need and to see if your need conflicts with the other person's need. Because if it does, see if there is another need of yours that could be fulfilled in that situation. If the answer is no, give yourself the right to withdraw, give yourself the right to say no, while leaving the other person the choice to continue.
Second: consider your need but do not impose it on the other person. Once you have identified your need, it is up to you to verbalize it. You have to tell the other person, but without forcing him or her to fulfill that need, because everyone likes to have the choice. I'd like to digress for a moment and make the distinction between a desire and a need. Because not satisfying a desire can lead to disappointment. But not satisfying a need, it creates a malaise, it affects your value. So it's very, very, very important to be aware of your need and to take care of it yourself.
Let's take an example. We are organizing a trip to the south. My needs are to go and rest, to sleep and to have a good time together. My partner's need is to move, to visit and to have a good time together. There are two of our needs that are contradictory, that come into conflict. What is important in this situation is to see which of these needs is the most important for me and is there a way to satisfy at least one of the needs, to make a certain compromise, but without sacrificing our needs.