Okay so I am new to this...but. a little background information...I have been with my husband for 6 years we married last october... our relationship is usually pretty good and we really are like best friends. However, his child.. our stepson is 11 years old and has been very manipulative since day 1. Through out the years I noticed something wasn't right with this kid but I couldnt quite put my finger on it and didnt know how to explain it to anybody. My parents and my sister have also picked up on it. I have talked to my husband about it the whole time we have been together but he has always told me I'm misreading situations and dismissed my concerns. I believe ss is extremely passive agressive and.possibly narcissistic. So ss constantly argues about anything and everything....so this past weekend I wrote down everytime he argued with me....we had him for 5 hours (it wasnt our actual weekend to have him) and I had 3 pages of examples of his constant arguing. Which my husband finally saw! He also talks to me in a belittling and demeaning way...for example he was telling me about an ice mummy he learned about in school...but instead of saying that.. he's like "do you know who this is"...its just weird wording and his tone is snarky!!! Also a few weeks ago he stole 900 dollars from me....and when confronted about it he said it's because he thought I forgot about the money (I had left it on the counter) and basically justified his actions and then blamed me. Which is a continued theme. So  we actually took his xbox and all electronics which he is obsessed with. Like I took it out of his room and am storing it at my parents so he doesnt have access. He undermined our punishment for him and has his friends playing on his account....which we found out about... he has no remorse for stealing the money..it was actually a huge deal for him to even apologize to me...my husband has really messed up with this whole situation....okay fast forward a few weeks.....my ss behavior has gotten worse....I literally cannot have a conversation this this kid with out him arguing or correcting me. I tell my husband this and he agrees and notices it...Monday night we have him and he turns into a "stepford"  kid..mhe says hi to me super loudly (he has not said hi to me in months)...he was being super helpful around the house...played ball outside with  my husband (which is good) ..hes talking to me like a normal kid but it's to excessive...he starts giving me the creeps ...i literally cannot get a work in to my husbandneith out him interjecting...as the night progresses I realize he has totally manipulated my husband and me...and have excluded me from all activities...they were sitting on the couch watching a foot ball game...which they have never watched one before!!!...never even offered for me to come sit with them...we have 1 large couch and they took up the whole thing so I couldnt sit down.....so I went into the bedroom....and after like an hour my husband came in and asked what was wrong..meanwhile ss starts throwing a ball making all this noise has knocked on our door line 8 times in a matter of like 15 minutes for my husband to come out..eventually my husband saw what he was doing...but I kind if feel like it's really obvious and I shouldn't have to be pointing this out all the time...

Also last week he mentioned to my mom about me dying. Not as in curious about death but as in when I am going to die...my mom said the tone sounded very calculating..and in the summer time he also told my mom. In great detail how he was torturing these bugs and like staking them and stuff ....which could be nothing boys are kind of gross like that lol! But needless to say I'm really creeped out...and just have a really bad feeling about him. 

I'm not quite sure what to do...I'm really tired and frustrated with dealing with this behavior constantly. Any advice? Thank you.