I want to leave my SO house because of his ungrateful friend
Is his friend really that bad? Why do you want to leave?
Because I don't want to put up with his friend.
It is okay to leave, they shouldn't expect you to stay when they are not being nice to you. It would be better to talk to your boyfriend and meeting elsewhere.
No, I'm leaving this house and taking my things like I wanted.
Thats also okay if you really don't want to be around them. However be aware that your boyfriend might be upset that you didn't talk to them first. Even if he wanted you to unfairly stay, you could at least tell him your reasons for leaving before you do.