What was the relationship between Caiaphas and Peter?
Peter followed Jesus at a distance as far as the courtyard of the palace of Caiaphas. Later, Caiaphas sat on the council that judged Peter and John. Matthew 26:57-58; Acts 4:5-7
What the Bible says
Matthew 26:58
And Peter followed him afar off, even to the court of the high priest. And going in, he sat with the servants, that he might see the end.
Douay-Rheims Bible (Challoner revision), public domain.