Love is a sacred and noble emotion. In other words, love is a connection, formed by a stream of positive emotions that you want to share with anyone. So when your partner wants to leave you, ask yourself if you really love that person.
Sometimes it is your indifference that makes the other person feel hopeless and decide to leave, sometimes they feel that they are interfering with your relationship with someone, they will blame and torment me so much. Answer your own questions, free them or tell them to pull.