A lock with no key is just a wall. Make sure the boundaries you set still have a way back in.

A boundary with no door in it stops being a boundary and becomes a wall. Limits are healthy and necessary: you can decide what you will not discuss, who gets your evenings, how someone has to treat you. The difference between a limit and a cut off is whether there is any way back for a person who changes. Walls are easier, and they are permanent in a way most arguments do not deserve.

Think about a line you drew in anger. Decide what somebody would have to do to be let back through, and tell them if they ask.