Updated: Apr 4
If the day comes that their actions stop matching their words is the day you need to stop investing in the relationship. You'll be making a HUGE mistake if you were to continue to give them more chances because what you will be showing them is that you're too afraid to walk away, that you need them in your life, and that your happiness depends on it. You'll be giving them power over you. And you're going to be completely miserable.
When you show them through your behavior that you're not afraid to walk away, that you won't settle for less than you deserve, if they truly care and want a future with you, then they won't do things that will jeopardize your relationship because they know you will simply walk out that door. And if they still treat you like dirt, then it just proves that they don't really care if they risk losing you. And in the end, that is not the type of person you want to be with.
Remember, the day you begin to tolerate neglect, infidelity, or abuse, is the day you'll no longer be sharing your life with them, you'll be giving up your self-respect, dignity, and peace of mind for them.