It's difficult to understand the context of this sentence.

That issue is irrelevant to our discussion.

His opinion is irrelevant to this issue.

They built a deep emotional bond before they had a physical relationship.

He is an expert in international relations.

His success had a cause-and-effect relationship with his efforts.

There is a complex love triangle between them.

This is the book that I am reading.

He and I are related by blood.

His claim does not match the actual relationship.