For a bit of context ive been with my partner for 2.5 years and we moved in together around 6 months ago. He has a DS9 and I have no children. DP has his son every other weekend and also dinner twice every week. I like my step son, he's not a bad kid. I've noticed this before but it's more apparent since we've been living together. SS9 has to be right about everything. He's been here the last 3 days and to be honest I've found it quite tiring. You could say to him the sky is blue and you'd be wrong. He doesn't necessarily 'argue' with you but will try and shut you down immediately. We'll be watching TV and DP will say something like did you see that dog over there? 'No, there wasn't a dog'. Yes, there was. 'No there wasn't, if you carry on saying there was then I'll leave the room'. He also gets wound up very easily, in situations you wouldn't expect someone to get annoyed.
I was really looking for tips on how to deal with this. As I said before, he's not a bad kid and we get on well but I don't have any children myself so I'm not too sure what the best approach would be? It's exhausting having a basic conversation with him.