People with healthy boundaries understand that nobody is obliged to hang around in the hopes that they will improve.
Boundaries are important in every relationship. You have to still be your own person even outside the relationship.
You’re not a rebound he can get under while he gets over someone else.
You say the words, ‘I love you’ and you wish you could take them back from anyone who’s heard them before because looking at her, she’s the real thing and the only person you want to spend the rest of your life loving.
You’d rather keep your thoughts or feelings to yourself than risk hurting your partner’s feelings or starting an argument.
She’ll love him unconditionally thinking that’s enough.
And you did everything you possibly could, only to lose yourself trying to keep someone who was never going to be yours.