There are varying views on marriage. I'm under the impression that once you're married, you 'got em,' so now you can relax and rest assured that no other wily woman is going to get her paws on your man. However, there are also the type that are jealous and worried, and not necessarily because they don't trust their partners (or maybe for exactly that reason), but because humans are fickle and not always creatures of habit, but sometimes creatures craving change and spontaneity.
My parents had a rule that one could never be alone with a member of the opposite sex. As a result, I got dragged along in the Buick for some road trips to Olympia, listening to dull politics talk while I stared out the window, kicking my feet at the front seat. I can't imagine how I would have ever reacted if the grown-ups decided they were attracted to each other and who cares about that girl in the back seat, she's just a kid, we can accuse her of making it all up with her vivid imagination.
Me? I wouldn't say I'm jealous per se. I don't go out a lot of times when Steve does because I'm a homebody and I don't like bars. I don't like watching frat boys play flip cup, or listening to terrible juke box tunes. I don't like hearing people puke in bathrooms and I don't like watching sloshed girls go home with creepy, ugly, pathetic guys. I also don't like concerts. So Steve goes out, and I ask him for a run-down of the events when he gets home. Just the highlights. Who got in a fight? Who won poker? Who passed out drunk?
But if Steve were to go out with anyone other than the normal crew, I'm sure I would become a bit more suspicious and possessive. So what behavior is ok and what is forbidden amongst married couples? Is the man going out to lunch with another woman ok? What if that woman has long legs, a short skirt, and implants? Or what if that woman has bifocals, headgear, and a mole sprouting hair? If I'm ever faced with that question, I would say, "what does she look like?" But should that matter? Sure, humankind is fickle, but isn't there somewhere that trust and precaution meet? Like a railroad track meeting the road: a pain in the ass for the drivers, but serves a purpose and saves a lot of wrecks.