How do I remove guest accounts on my phone x and my air pad

I'm sorry for the misunderstanding. That isn't generally what is meant by a "guest account" in computer terms. You can add as many email accounts to your iOS device as you want.

Deleting an email account is straightforward. Go to Settings>Accounts & Passwords. Find your son's account. Tap on it. Tap "Delete Account" at the bottom of the page.

If you're using a Google App (Gmail or Inbox) and you're seeing an account that's not yours there, you'll need to follow the instructions for the specific app to remove it.

If you still want to let your son use your iPad but not mess things up, explore Settings>General>Restrictions>Allow Changes. Just don't forget the passcode you create for Restrictions!

In case you mean the actual App update is requesting your sons Apple ID, which uses his email address, you will need to delete the App from the iPad and iPhone and redownload it with your own Apple ID.

Apps are tied to the Apple ID (combination email and password) used to download them and are forever tied to it, and will require it to update.

If your son used your iPad and downloaded an App with his Apple ID, its tied to it, and would need to be removed so it stops asking for its password.

Make sure your own Apple ID is signed into Settings->iTunes & App Stores->Apple ID, and delete the gmail app, and redownload it with your own Apple ID.

It's not possible to have guest accounts on an iOS device. iOS devices are single user devices.

Perhaps you can provide a few more details about what you're seeing and what you're trying to do.

Good luck! Let us know if you need anymore help.