A boundary is for a behavior that you won't accept from another. There must be consequences for failure to comply or it isn't a boundary.
Ex: If you do this:
The consequence is this:
You must follow through with your consequences, or your boundaries mean nothing. Therefore, only set boundaries / consequences you are prepared to uphold.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl