In an emotional relation (between 2 persons), the suffering person has more need to get relief from hurt and hence will be open towards change. However, change in a relation needs to happen for both sides. For long term healthy relational growth, change in a relation is a basic growth point. If only one is willing to change or both are resistant to change, the relationship stagnates to the extent of rigidity or pulling back from relating further to the person.
Especially in long term relations like couples, siblings, the effects can be damaging for a lifetime. Be open to change & live a worthy relation than stagnate & waste precious life.