Doesn't he deserve the benefit of the doubt with this unless I know otherwise??
mybest,
Do yourself a favor and approach this as if he's having an affair. The probability that he's not having an affair is close to zero.
When I was young, I worked the night shift for awhile. I was an aircraft mechanic and I worked with a male-only crew. Regardless, there were plenty of opportunities. There were women that worked at night cleaning the aircraft. In fact, let me tell you about Cheryl Lynn (she liked to be called Cherie). She was a tall tan, long legged 19 year old that I was nuts about. Neither of us were married, but she did have a boyfriend. I swapped lots of slobber with that hottie while at work and we went on several dates. I still have fond memories of Cherie. (That was back when the Journey's song "Oh Sherrie" was popular.) Those were the days...