My er, brain, struggled to cope with so many characters all at once as I can barely recall their names or who is married to who. Sean looks like a slightly disreputable type and his wife over-anxious. None of them seem to be having fun (apart from when the women got stupidly drunk) and it's meant to be a holiday - but I expect that's the point.
I'm not sure that any of the characters are particularly likeable (apart from the younger lad) and if you were reading the book why would you turn the page if you don't like them or care what happens to them?
Thus far, the men (apart from the dishy but scruffy Sean) just look anonymous and grey. Jake is worse than the average moody teenager and I feel that someone is holding a nasty secret. I'm sure there are red herrings but I'll stick with it though to see what happens next.