I've been in a similar situation before. Unless your GF decides to put boundaries in place with her son, there's little that you can do. Don't feel bad about leaving if you have to. I ended up needing to do that  in the relationship I was in because my BF at the time completely refused to explore any other options for sleeping arrangements. If she won't make any changes based on how you feel, this is not a good sign for a future life with her and this won't be the only thing she'll refuse to make changes about either. She needs to support her son of course, but she needs to also help him self soothe. It's a tough situation. Anyway, I wish you all the best, and again - do what's right for you. If you know you can't live with this long term and she won't make changes, then do what's best for you.

If you have tried to talk to her about this with no luck, theres not much you can do.  I wouldnt move in with a person who doesnt parent their child.  I guess you could maintain separate residences and date but you will probably end up splitting eventually anyway so it might be best to break it off now.

Sorry to sound so pessimistic but if you read around on Steptalk, it is seldom or never that these situations improve.  Its a bummer that you sold your house.  Good luck.

It's worth having a talk with her about it. See if she is willing to do the work of parenting him properly, and maybe just needs support, or if she is a hopeless case. Parenting would start with getting him to sleep in his own bed like I'm guessing she probably did as a child, you did, and most other kids did before the whole "letting the kids run the house" thing took off. If she balks at that, she probably falls into the hopeless category.

He also needs to be taught basic manners and respect. If he isn't parented, there is a very real risk he will end up down a bad path as a teen and young adult, with problems in school, problems with the law, drugs, or even abusing his mother. Nobody wants that for their kids' future but these days it seems many people aren't willing to parent and do what they can to prevent all that. Good luck. Don't just live with things as they are. 

 There are other fish in the sea.  Find one that doesn't have a kid or parents them.  You can tell what kind of parent they are by how their kid treats you.  
 

Has she given any thought to this kid treating a teacher they way he treats you?   Are the extended family members relived he can't spend the night?  Do you really want a partner who willing chooses her son over you constantly?   Do not let her move in until she can parent her son into be better behaved. Once she moves in and it falls apart , it will be very difficult to get rid of them. You have leverage right now to get her to make a change.   

Yeaaaah... Sometimes love isn't enough. She isn't raising an independent self suffficent little boy. I fear your troubles aren't going to end when he turns 18. She is creating an unhealthy codependent relationship. It would be one thing if you were able to have a conversation with her and she didn't immediately turn defensive. 
 

It's hard to ask her to fix or change when she doesn't see any issues. My husband's kids were around that age when I met them and they had issues with their mom they NEVER had at dad's house. Kid's will behave to a certain extent how the adult in charge allows them to. Good luck!! 

I'd say it's not working out for you.  No sense getting into an argument as she defends him.

This happened to me too. Always caused an argument however I was not prepared to sleep in the spare room every wknd making way for a child to take my place in the bed, and I wasn't happy for the child to sleep between us when he was brought in early in the morning. DH also used to let him fall asleep on the couch and then carry him to bed....same issue, kid woke I'm crying numerous times through the night. DH once offered to put a swag on the floor on weekends....not for the kid, for me!!! Then when I declined that he ended up laying in kids bed every night till 11pm and every other time he woke up through the night. I kept my foot down and won the battle. Had to give an ultimatum though. "If this kid doesn't start sleeping alone in his own bed I'm leaving and you can be in a relationship with your children" 

We argued for about 4 years. I copped "you have a problem with my children" and "why can't you just love them as your own" and "I bet when we have a child you will change the goal posts" yeah maybe, but that would be OUR child so it's different. 

Your SO is being a lazy parent, is clinging to her child, and is not considering anyone feelings except hers and the kids. Welcome to step life where you don't matter, always come last and have no say in anything. Leave now.  

Point of clarification: it's not the kid who is the problem, but it's your GF's parenting of him.

The kid is acting like a kid will act without rules and boundaries. He has been taught that he can get what he wants when he wants so long as he screeches and cries loud and long enough. Young children are inherently selfish, and not being selfish is a learned skill, not an innate one.

So, I would say something to her like this:

"GF, I love you, but your parenting style does not create the kind of environment I want to live in. I don't like that I can't talk to you about issues because you get defensive. I don't like that you allow your son to dictate our schedule. I don't like that you allow him to sleep in our room without considering how it makes me feel. I don't hold any grudges against him, but I am starting to resent you for not parenting him and for making me feel poorly about a 5 year old. This relationship just isn't going to work for me any longer."

Always take it back to how her parenting in the problem, not her kid. She may not hear you say that it's her NOW, but perhaps after the next BF, and the next, and the next tell her the same thing, she'll take a hint.

Just decide rationally if you are willing to be one of the boy's primary care givers. If it's a challenge you are willing to take on, no matter what, then you'll find the strength to do what needs to be done. That includes the monumental efforts it would take to change your SO's parenting style. But, why carry that cross? You may end up being a martyr. If, you feel in your heart that is your true calling, then pick up that cross and carry it. And never complain about it, because it is your life's mission. But, the fact that you posted this question is enough of an answer. 

I just ended a relationship because she had a five year old brat. (There were also other reasons.) I've read on this forum that having a step-child is VERY difficult even under ideal circumstances. Good luck. Probably a good idea to move on.