The context of the following conversation is Casey was lying down in their bedroom.  Kai laid down on Casey's side.:
Kai says It was so nice just to chill with Casey in bed..
The friend responds That must've been relaxing..
Kai responds It was, especially after our busy day..
The friend responds What did you get up to?.
Kai responds We went for a long hike through the forest, it was great fun but exhuasting..
The friend responds I bet it was!.