Common? Uncommon? Well like most things, it all depends on the crowd that week! "He" will certainly be dressing in boxers etc this next trip, it's extremely unlikely he'll be the only one, there are always a few brave souls out there to set the bar. We've seen neon night for example where most of the gents were sporting neon boxers, with or without tops, other nights there may only be a few. But do you know what? It doesn't matter. I say go for it, if you really, really feel uncomfortable it's never far to go back to your room to change! And to be honest, it's likely to be very warm in June, and the idea of stripping down to your undies might be very appealing.