@Matt-And-Linda0, three 18 year old males (with bad screen name) sound slightly alarming, but might be nothing. I would probably ask them to show photo ID when they arrive, and write down the car numberplate. (I hope you meet and greet in person). If you don't allow extra guests, you need to make sure that doesn't happen in case a party is a possible worry. Do you live nearby or are friendly with the neighbours? Maybe keep an eye on noiselevels etc. I googled BangBro and it is a really bad pornfilm site. To be honest, I would now have a conversation with him questioning his choice of name, and asking that he make his real name available on his profile. I would quite possibly consider cancelling this booking, regardless of penalties. But he might cancel it himself, if you question his motive for a porn name on his profile? Take a parental role, nice but firm?
All the best.