I hope this is in the right place. Have been with DP for 5 years. He has a 12 year old son who has always lived with him. I moved in around 1 year ago. Before I moved in my relationship with DP's son was manageable. I was like an aunt or a teacher or another influential adult in his life. But since I've moved in, my DP's son has been acting in a way that would suggest he doesn't quite understand the dynamic in the house.
For example, the other day I made myself and my DP a cup of tea and gave him a biscuit with it. His son then started asking why he wasn't also offered a biscuit- I told him he's free to take a biscuit if he wants it. In the morning on my days off I'll ask my DP what he fancies for breakfast. If DP's son is there, he'll get upset and make a point about me not asking or including him (of course I'd make everyone's breakfast in such a situation not just my DP). The dynamic is making me feel very uncomfortable.
He'll insert himself into adult conversations that don't concern him, so much so that we have to be careful what we say infront of him. He seems always to have an opinion about adult issues (mortgages, cars, medical issues) that he knows nothing about, and will offer them when me and DP are in the middle of an important discussion.
I'm probably not explaining it well. It just feels like my DP's son expects me to be treating him like another DP/exactly like his father and not the child that he is and it's creating this weird atmosphere where I cannot be myself and exist in a romantic relation with my DP.
Has anyone experienced anything similar? Is this normal?