If i were invited by my friend for a free tip with his wife and we were all sharing the same room AND THEY ARE STILL IN HONEYMOON PHASE. I would have a stern talking with my friend about him being a moron.
And would have dissuade any friend from coming along. Sometimes authors are kinda dumb in the weirdest of ways.
Even in our teen years we tried to separate couples from single people to give them some space.
If possible they had separate rooms if not then beds at least.
Having group activities together doesn't mean that EVERYTHING IS FUN TOGETHER.
It gives of a feeling that author is a person who doesn't have any friends and imagining how it would be without thinking or knowing the drawbacks of group vacation;activities.
You rent a big house for example. It's expensive to rent for a single couple so you invite friends + more fun. You cook some food together (grill), drink, play some games and at the same time some couples disappear to do their own activity and of course they usually have their own rooms (if possible). And everyone is happy.
If during our friendly outings those rules wouldn't be preserved friends who have partners wouldn't waste their time and money to travel together. They would go 1 time but after that whilst they will say it was fun con's of going together would outweigh the pro's.