My least favorite part of conflict is not the conflict itself, nor is it any argument that may result. It's the aftermath. It could be that the conflict remains unresolved. It could be that things were said that deeply hurt one or both people, and that hurt feelings have been lingering for quite some time and only recently voiced.
Whatever it is, in these situations, the conflict has not come and gone like a quick rainshower. It was more like a hurricane, and there was damage left in its wake.
Now, it's time to figure out how to move forward.
It's time to figure out whether and how much to trust the other person again.
If you do choose to maintain the relationship, then each must set about repairing the relationship so that each person involved feels able to trust again.
And in the meantime, while you are in the midst of repairs, there is that ache of missing someone, of missing the closeness in a relationship.
That's my least favorite part of conflict. That ache.