Ghosty, my husband has spent the better part of the past year traveling extensively (Mexico, China & East Coast)with a gorgeous leggy red head from his department. They have been sharing rental cars, and pretty much having all meals together and never once has jealousy or insecurities entered my mind. We call her his work wife lol.
I agree that affairs usually start at tr workplace, but there has to be something lacking in the marriage to begin with for a spouse to even entertain the thought.