仲良かったり悪かったり浮き沈みが激しいのって英語でなんて言うの？

"仲良かったり悪かったり浮き沈みが激しいの"
- Their constantly switching between being on good and bad terms.
- They'll be friendly one day and fighting another.
- Their relationship is full of ups and downs.

喧嘩をしなければお互い理解し合ってていい関係なのに、すぐケンカになっちゃって二人の関係にすごくアップダウンがある
If they didn't fight, they would be able to come to understanding and have a good relationship. However, they easily fight and their relationship is full of ups and downs.