1, communicate with roommates
We should have a good communication with our roommates. After all, this house belongs to you two. She should ask your advice before doing anything. You can just tell him that you don't like her bringing her boyfriend back, so you will feel embarrassed. I think the average roommate will feel embarrassed when he hears this, and it won't happen again.
Then if she still doesn't listen, tell her that if she listens, you won't share the rent with her and move out. After all, women don't live with boyfriends. It must be inconvenient for boyfriends. At this time, if you don't share her, you have to bear more money yourself. Most girls don't want this.
Step 2 swap roles
If your roommate can't listen to anything, I suggest you change places. After all, it's really embarrassing for roommates to bring their boyfriends back. Most of the time, you are embarrassed to go out and get things, because they are all glued to the living room to watch TV dramas. Moreover, it is inconvenient to go to the bathroom with a man in the house, and it always feels strange.
Don't be wronged at this time. After all, there are so many people looking for a roommate, and you can find a better one without this. Maybe the next living environment will be better and closer to the place of work.