My SS10 plays his parents and calls the shots. DH seems to think he has all the control, but his control is SS10 actually manipulating him. For example, today is my BS6 birthday. He loves to fish and that was what I planned to do with him. Well last night after dinner, SS10 tells DH that he wants to learn to work the trolling motor on our small boat so he can take BS6 fishing. I tried to explain to DH that this was simply because SS10 wants to feel like he is the adult. (He constantly corrects BS6 and BS2. He also thinks he is an adult and tries to talk to me like he is my equal. - cue the horns sprouting from my head)
DH thinks its so "great" that he wants to take BS6 fishing. I disagree. I think it's a ploy to get to drive something (yes I know it isn't fast, but the kid just wants to be in control.)
SS10 is mean to BS6 more times than he is not and shares nothing with him. DH got mad a few weeks ago because my mother was keeping the kids. She would not allow SS10 to go under water while swimming because BS6 had swimmers ear and the deal was if they got in the pool they could not go under. SS10 agree to this and then tells DH when he gets home that gma is mean because he couldn't go under. (An example of the manipulation.)

Am I overreacting and reading too much into this?