How to deal with emotionally immature parents

Work on yourself first.

Do you find yourself just as frustrated, hot-tempered, or reactive as they are? Or maybe you bottle everything up inside, only to explode later—on your spouse, your kids, or even your pets. That’s a sign that you might be just as emotionally immature as your parents. It means you need to work on yourself first.
Being the louder or angrier one doesn’t make you tougher or more powerful—it just screams, “Hey, I’ve got issues too, and I can’t deal with your crap!”

Set boundaries.

Do your parents come and go whenever they want, at their own convenience? It’s time to decide how often you want to see them. For some people, it’s once a month; for others, once a week.
Then figure out how long those visits will be. Is it just a couple of hours? A quick lunch? Do the same for phone calls—decide when and how often you’re willing to engage. Setting boundaries isn’t being disrespectful; it’s being emotionally responsible.

The “Let Them” theory.

Once you’ve decided how often and how long you'll interact with them, let them do or say whatever they want. If something triggers you, repeat in your mind: “Let them.” This helps you release the need to control the uncontrollable—their actions, their words, their intentions.
Then say to yourself: “Let me.”
Let me excuse myself from the situation.
Let me ask for the check so we can get going.
Let me say I’m tired and need to rest.
Let me turn on the TV or pull out my phone to redirect my focus.

These small choices help you keep the peace while staying grounded in your own emotional maturity.