What do you do when you are with someone that you dont like their children? For legit reasons as in being disrespectful, hard headed etc?

When you say with them, do you mean like a relationship or just out grabbing lunch with them? If you just mean grabbing lunch, I wouldn't say anything since I don't have to deal with them often. If you mean that you are in a relationship with this person, then I would talk to them about it. This is why I avoid people with kids. I'm not ready for kids, so I don't want to deal with a significant others kids/baby mama drama. You should talk to her about it when the kids can't hear. Tell her that her kids are really disrespectful towards you and that you want her to start paying more attention to it and discipline them. If that doesn't fix it, then you should just leave her. Ain't nobody got time for disrespectful kids and if it isn't fixed now, it wouldn't be fixed when their teenagers.

If the parent is a friend, I make a joking comment like "Are they always acting like this, or is it only when I'm around? I don't know how you put up with it. I would be drinking a bottle of wine every night" and say it with a laugh.