Why didn't Kieran and Olivia cross paths with Sean and Gabby on the day of the storm?

Why didn't Kieran and Olivia cross paths with Sean and Gabby on the day of the storm? Weren't they all the caves at the same time?

I’d have to check the text, but I think one couple was in one cave and the other in the other one.

It only makes sense that they were in different caves. I wonder if the couples could have been in the same cave but in different areas - when the story described Sean and Gabby's experience in the cave, there were different paths or forks to take. I suppose that was possible?

They were in different caves. Kieran talks about the different caves. Sean and Gabby go in the North Cave. Kieran and Olivia were in the South Cave. I think Sean takes Gabby to the South cave to keep her away from Olivia.

As others have said, they were in separate locations - Sean specifically took Gabby to a location away from Olivia. I think I read - someone correct me, please, if I'm wrong - but Sean was really attracted to Olivia and if he could have, would have chosen to be with her. He is not with Gabby because he's really interested and so he trying to avoid anyone knowing who he is with or where.

They were in separate locations. I think even if they had been in the same cave they might not have seen each other with all the twists and turns in those caves. And remember Sean was one of the two that had searched and plotted those caves so completely, so he knew a lot of the nooks and crannies that no one else knew.