FI and I are getting married and having our reception in a place that strictly prohibits smoking and drinking. We signed a contract stating that we understand these activities are not to take place on park grounds and we do not want these activities at our wedding/rehearsal. FI's cousins told us that they plan on bringing a flask anyway because "you can't expect us not to drink at a wedding." We tried to explain to them that we signed a legal contract and that we cannot have alcohol on the premises, but they said that "it doesn't matter; nobody will really find out. We're going to bring one anyway." FI's brother is also telling us that he still plans on lighting up.
What the heck am I expected to do in this circumstance? FI and I absolutely do not want smoking and drinking at our wedding, so we were both relieved that the facility doesn't even allow it, but it looks like it's going to happen anyway. We're renting a building through the county park system, so it's not like a ballroom that'll have staff there to monitor. Someone will be by to check on us, but that's it.