Are they being overly needy or do you experience their feelings as demands?

Children made to feel responsible for their parents feeling, or look after their parents in some way, believe it's their job to keep people happy.

Now, when someone is expressing an emotion, we can experience this as a demand upon us. This can cause resentment and self-abandonment, because we don't feel we have a choice. But as adults, there is always a choice. Other people's feelings are not demands upon you. It's not your job to make people happy, in fact it never was.