Since I've never heard of this 'Layton Benton Valentine's Day Whorerror Story' before, it's difficult to say. It might be a story that combines elements of Valentine's Day with some sort of mystery or error. Maybe Layton and Benton are characters involved in an event that went wrong on Valentine's Day, but that's just speculation.
There's not enough information to really know what this story entails. However, if we break it down, perhaps Layton and Benton are people who had an experience on Valentine's Day that was so out of the ordinary or wrong (the 'whorerror' part which is an odd term) that it became a story. It could be about a failed Valentine's Day date, a misunderstanding between them related to the holiday, or something more complex and unique that only those familiar with it would understand.