You know what, I think it is time to have a little sit down with FI. There is so much planning to a destination wedding, the last stress you need is all of his side worrying more about finding some good weed and getting some action while at your wedding, than the fact that the two of you are about to become a married couple! I mean, I would not want to get caught in a foreign country, smoking an illegal substance, and getting thrown in jail! How old are these people? They can do that at home. With that being said, I would also remind DFI that this is about the two of you, not about him and his friends. Maybe the boys could have their nite out b4 you leave. I would be upset...but then, it is just my opinion, coming from a mom.
Good luck honey.
Lizzy