They are famously tough to deal with in relationships because they frequently manipulate and exploit others around them to suit their own wants. One characteristic shared by narcissists is a dislike of seeing others happy. Here are some of the reasons a narcissist could feel this way:

They are threatened by your happiness: Since narcissists have an exaggerated sense of self-worth, they are frequently threatened by those who are happy and successful. They feel that they are the only ones who deserve to be happy, and they may get envious and resentful when others are pleased.

They desire to have authority over you: Narcissists want power and control over others. They may be afraid that if you are happy, you will grow independent and less dependent on them. To preserve their sense of power over you, they may try to ruin your happiness or generate conflict.

They lack empathy: Narcissists lack empathy and are unable to understand or empathize with other people’s feelings. They may become furious or disappointed when they see you as joyful since they cannot feel the same feelings.

They seek attention: Narcissists seek other people’s attention and adoration. They may feel forgotten or overlooked if you are pleased, and will strive to draw attention back to themselves.

They have an overblown feeling of superiority and frequently believe that they are better than others. When they see you happy, they may feel intimidated or belittled and may try to tear you down so that they can feel superior once more.