Not his father

[glatt]

Welcome to the Cellar.

In a nut shell, you and the mom need to be consistent. You need to enforce the rules in the same way as one another, and you need to each enforce the rules the same way, every time. It's easy to get lazy and let minor things slide, and then they build up and you can have an over reaction when the final straw sends you over the edge. That laziness actually leads to more work in the long run.

Kids want to know the rules. They want to know where they stand. They will test the rules, and if you don't enforce them consistently, they will become distressed. Don't let the minor things slide. Enforce everything. Every time.

I'm not saying your rules have to be strict. I'm just saying that if you bother to make something a rule, you have to always enforce it. If you want to make a special case about something, you should announce that this particular time, for whatever reason, you aren't enforcing the rule.

And as for listening, it helps to squat down so that you are right in their face, lock eyes with them, and speak clearly and calmly. It's more likely to sink in that way. They can't ignore it.

You don't want to be training them to only pay attention when you yell. Talking at a normal volume should be enough. Just speak firmly.