When one partner sets out huge expectations and outlandish terms expecting the other to change and defer to them. The relationship would be a dictatorship.
The next one might not seem obvious at first.
They hide from each other
When one of them (or both of them) is constantly hiding shit from the other one. That whole “if my girl/boyfriend calls, I’m not here!” or anything like that.
I dated a guy for awhile who was a huge drunk and tried to hide it from me as much as he could.
Found out after we broke up from a couple friends that they would occasionally run into him at bars and he would always ask them to not tell me they saw him drinking. –bagzilla