what happened on the fishing trip

The question is unclear about which fishing trip is being referred to. However, based on the search results, it seems that the question is about the fishing trip in the TV show "Gavin and Stacey". The fishing trip is a running joke in the show, and something happened involving Bryn and Jason on a fishing trip some time before the shows events. The mystery shrouding the event suggests it was highly embarrassing and potentially sexual due to the taboo way its talked about. There are plenty of theories about what happened on the fishing trip, but it has never been revealed on the show. Some theories suggest that Bryn and Jason fell into the water and had to strip down to their underwear to warm up, while others suggest that they kissed but then realized that they were related. However, these are just fan theories and have not been confirmed by the shows creators. In an unaired scene, Jason met Bryn outside Gavin and Staceys wedding reception and attempted to clear the air, saying "I never told anyone, you know that". However, this scene does not reveal what actually happened on the fishing trip.