Re your original question about boundaries or control.
My take on it is this.
Boundaries are what you are willing to accept in a relationship. In a healthy, honest relationship someone will set a boundary and the other person will accept it or not. It's healthy to have boundaries and to state them.
What's healthy is saying, "you knew that was a boundary and you accepted it and then did it anyway, so I don't want to be with you anymore."
What is not healthy is when someone doesn't accept your boundary but you force yourself to be ok with it when you're not, or you end up manipulating the situation so they can't break it.
Some boundaries are unreasonable either objectively or subjectively and the other person will think, "that's ridiculous, I don't want to accept that!" In which case, they should also say, "well I'm sorry but that is important to me" and either make a compromise or leave the relationship themselves.
What is unhealthy then is them continuing to do it but hiding or lying about it.
Everyone's boundaries will be in a slightly different place because what is acceptable to people is different.
I've ended both friendships and relationships because my boundaries were crossed. Some people have told me I accepted too much and should have walked away sooner, others felt I was heavy handed in ending them. Because people's boundaries are different.
As others have said, communication is the key.