Husbands and secrets

What would y'all do if you found this in your husbands bag? My husband is in the national guard and he works on a tow boat 21days on and 21days off. I just found this hotel key and I'm not real happy but I'm not mad... honestly I want to cry my eyes out. He is asleep in our bedroom with out 6 month old daughter right now and I'm fighting back tears and the urge to scream because not only do we have a 6month old we also have a 6year old lil boy. This is probably the shittest thing that could happen with it being this close to christmas. I just need advice on how to bring this up? I'm very worried and don't know what the hell to do anymore...