Depends on how many of them and how often that you are trying to explain them. If it is one night a week heading out to play softball/drink some beers( or whatever). Tell her the truth. Just us guys. We don't have to watch our language or our manners and we can decompress. If you are trying to slip out and get lap dances at the local strip club..that's a whole 'nother explanation. Good luck with that one.