You have a DH problem. If your DH didn't teach his son manners or put the a$$hole in check the minute he opened his mouth to you, then you are in for a very long rough ride. No parent likes to hear anything bad about their kids, but not doing anything about the disrespect is proof of who is first priority, and unfortunately that is not you with your DH.

Your relationship is fairly new, compared to others on here, your "love" for your DH will slowly turn into resentment, because he's a sh*tty parent. I would walk away and never look back, life is too short to live with a man that has no respect for you.

I dont have a lot of advice, I've made plentry of mistakes on my long step journey.  I had 3 SKs and 2 BKs.  I'm guessing this "boy" feels threatened by you moving in, he sees Dad's attention being diverted.  He probably fears your  (rational) influence which might change his cushy life.  After all, it's been his home and now there's another person living there, changing the dynamics.

Seriously, I doubt that you will change his opinion but you shouldn't have to put up with his disrespect.  What does your DH do when he says those things?  It's not a good sign if he doesnt defend you.  I would give some thought to whether you want to stay in this relationship, or in the home, anyway.  Maybe moving back and just dating would be best until the son launches.  But read around on this site because many kids like this son either don't launch at all or its a long time with Dad enabling every inch of the way.  Sorry to be so pessimistic. Good luck. .

If my SS20 ever behaved that way towards me, DH would knock him into next week. Your partner is allowing his kid to mistreat you. He's the real problem. 

Omg, my dad would have knocked my head clean off my shoulders if I had ever said anything like that! If your SO didn't react likewise, he's not worth the effort. His kid will get off with opening his mouth and pour forth his venom with no consequences only excuses for as long as it takes to drive you away. 

Now that SS knows he can do it with out any interference by his father.  He will ramp it up,  you must talk to your SO telling him you will jot be disrespect by SS and him.  If yoir SO doesn't do anything then it's time to move on.  Because you must have respect for yourself. And not allowed this treatment by anybody. Or all is lost 

Played imaginary happy family with daddy (pretending me and my 2 kids with hubby do not exist), expect i walk behind the 2 miniwives, tried to make daddy leave me with 2 kids under the age of 2.5 so they could go with daddy for 1 whole week on an all expenses funded holiday courtesy of daddy (with us not present of course during my and hubby's 4th wedding anniversary), sd's answering me back and doing inappropriate things to my kids when daddy isn't around, undressing my daughter without permission, trying to poison them with rotten unsafe food.

the sd's even while i was overseas with my 2 kids because my dad was admitted to hospital by emergency, guilted daddy with some imaginary bs sob story that daddy abandoned them for us (me and our 2 kids) and that we were the new family (aka replacement family);m, what they failed to admit or recognize was that daddy had tried many times tried to arrange meets but they refused with some bogus excuse or would change plans last minute

i remember 1 time last year when i was in my birth country for a few months with my 2 kids finishing my university studies and hubby thought for religious holidays to spend time with them and surprise2 they cancelled 2 days before, sd's actually messaged their brother who then told hubby. They couldn't go because their stepdad banned them from seeing hubby.  Hubby acted all surprised that they cancelled last minute and was so angry they couldn't even tell him and if he had known they would cancel and had no intention of going with him away, that he would have booked a flight to spend time with me and our kids (who would make time for him). 
 

i told hubby off how did he not see this coming!! They have everytime changed our plans last minute and made hubby jump through hoops like a friggin clown and playing him for a dumb fool, they have no respect for him and i told hubby that it was his fault for trusting they would honour those plans.

So now hubby prioritizes his free time around us because we are reliable, skids are not and such miserable people ranting on non stop about bio mum and stepdad. I have since 2 yrs ago refused to be around skids especially sd's. They report everything about me hubby and our kids. What we wore, what we ate, what we said, where we went, what we did etc... its a whole interrogation by bio mum that they're preconditioned into giving a detailed report and next meet will comment what bio mum and stepdad said in response to the above.

i told hubby i refused to be around them as this is a gross violation of my marriage with hubby and of my 2 young kids and sd's have no respect for us and i refuse any meets. Hubby tried once 1.5 yrs ago for a family wedding to covertly invite sd's and pick them up on the way to the event which I explicitly said if they were coming i would not be present as they are such rude disrespectful people and even Hubbys sisters wonder why they come because they do not interact with hubby one bit. 
 

barely 30mins after me asking hubby if sd's were coming and he said no they have other things and was sure about this, his eldest sd confirmed they were coming and hubby was to pick them up. I asked hubby again after if they were coming and he said no but in a vague way. The day before the wedding whilst hubby was at work and he messaged me if i was ready and packed, i told him i would not be going and that he did not respect me as his wife. I told him my boundary and he disrespected it and actively behind my back was bringing them along and was trying to play innocent victim knowing i would lose my shit in front of them all. He was actively trying to gaslight me. He claimed he would tell his daughters to not come because he knew he was in deep shit. I told him to get stuffed because he made his bed and he better sleep in it!!

after this he didn't dare to push the matter and push us to be together. A year later he thought wifey had calmed down to her boundaries around skids and gave a whole sob story by eldest sd that daddy abandoned them for us and their mummy neglected them and abandoned them too. I called bullshit on that story and reminded hubby if that were true, how come sd's had just recently cancelled a meet with hubby because bio mum and stepdad made them go on holiday to meet stepdads family. They weren't abandoned or neglected then and hubby was in silence.

2 yrs on and i stay my ground. Hubby has been reminded there will never be a holiday, a meet up involving me, our 2 kids with feral skids!! Its been over 2 yrs and his 3 kids have made no attempt to care about our 2 kids and ask about them or maintain a relationship but hubby lies that they adore our kids and so happy to have them and because we are overseas they can't have a relationship, to which i say "oh so videocalling is too much of an effort?"

there comes a point where you need to distance yourself from toxic arseholes and not feel guilty about it. You share no blood genetic relations to demonspawn, the only way you can have a relationship is by mutual consent and if both parties are pleasant. Since skid(s), are feral, a relationship will never happen

Yeah.... no. Hard pass. Time to find your own place again. 

He can either be YOUR partner and hopefully one day husband or he can continue to coddle his ADULT son. Your SO does need to make the decision.

That doesn't mean he has to kick an 18/19 yr old out- many kids aren't ready to launch and with most colleges learning remotely right now, the world is complicated. However, it does mean that his dad, your SO, puts his foot down and demands that his son treat your with decency and respect. If your SO doesn't do that... well, you can tell how much he respects you as a partner.

I have a 20 yr old SS who is autistic and a 16 yr old SS that is a douche. My husband will come flying around from another room the minute either of them even catch a tone with me. 

How does a relationship survive a divisive SS?

By having a non-divisive OH who recognizes that his ADULT son is being a prick.

If your OH won't recognize that his son is being a d-bag and won't work to launch him into his own space, then your OH is the problem here. If he wants an adult relationship, then he needs to prepare his life for one. Forcing his children to be respectful or telling them to GTFO when they are adult enough to do so is one of the ways he prepares for that.

Your SS may be the one throwing insults, but he's doing it with OH's blessing. SS is the symptom, not the problem. You should be asking yourself why your OH is okay with his son treating you that way.

Move back to your own place, and if your OH ever dislodges his head from his backside, don't move back in together until his son is launched and you two can find your own, new place. If that seems like it will never happen, take that as a big, red flag from God or the universe or whatever you believe in that this relationship is doomed.

During my short marriage, I have learned that step life is horrendous and stressful. I can honestly say that from the start I have loved my SS as my own. Never wanted to try to replace anyone or overstep my bounds. Just wanted to love this kid. Been so good to this kid. Taught him things his parents never taught him how to do, like tie his shoes, cook a little bit, sit with him to do schoolwork, etc. Over time, I have been betrayed by my H due to his inappropriate boundaries with his ex, and their child has major behavior issues that are a result of their poor parenting and the divorce and that continue because of it. My SS is 10, so his foundation has been laid, and any change is hard work. Change won't stick very well if others are not on board or don't even see a problem. My H is starting to open his eyes to some of this, and he is trying to make changes. I stay because we have a baby on the way, and because I believe we genuinely love one another. But if I knew what I do now going in, I really feel like I would have ended the relationship. It's good that you lived together before marriage. We did not, and it is once we did that stuff got rough, and the real deal of what was before me became apparent. And I say I think I would leave, despite the fact that my H and I have a beautiful relationship, and I loved him enough to say I do, which I do not take lightly. But the prior family is where the majority of our issues lie. Seriously, the majority. I find that I have to let a lot go, or there is no peace. When I do take a stand, it's an exhausting battle, and I look like the bad guy, the evil SM, nagging wife, I guess. It's not how I would like to live, despite how much I would miss my H if he weren't my H. But this stuff throws wrenches at us all the time. So, if you are not married and don't have kids together, just move on to a less complicated life.