Jealousy is, to an extent, encouraged in marriage in Islam, and so it is in many religions and cultures around the world. While some are born jealous, others are made so. Yet, some defy the religious, cultural, even commonsensical precept and choose to be unenvious. They care not for their wives, daughters, wards, sisters, etc.
I was told a story of a man, an ardent fan of Bollywood, the Indian films. He everyday tells his wife, while watching the films that the most beautiful and sexiest women are in India. The wife doesn't like that, yet she keeps mum. It disturbs her a lot for obvious reasons.
One day, the wife told the husband that even the handsomest men are in India. He was quickly aghast. He though repressed his infuriation but decided to never watch any Indian film henceforth. That's to avoid what he could have done to the wife should she repeat what she's just said.
A professor at Bayero University, Kano (BUK) once told us a similar, however far more upsetting story of one of his friends and his wife. She praised an Indian actor in his presence. He instantly slapped her, and that was the genesis of their eventual breakup. How unfortunate!
My word of caution here is: husbands should equally understand that their wives are also humans with feelings and all that. Don't only think that you are allowed to add another wife (for Muslims), and that's a licence to extol other women in front of your wife. You can do that but in discretion and, preferably, in her absence. Doing otherwise is sincerely speaking insensitive and inconsiderate.
It's said that what's good for the goose is good for the gander. So, let's be human, careful and considerate.
A personal experience
As newcomers in India, my wife purchased Indian traditional, unstitched attire. We went looking for a tailor and found one unisex male tailor in our neighbourhoods in Jalandhar. The tailor's shop is attached to his house; one can see the inner part of the house from the shop.
The tailor wanted to take the measurements of my wife, but I said no. That could either be taken by me or his wife who we saw peeping to see the "foreigners" her husband was speaking English with.
Surprised, socked and saddened, he called the wife. She came holding a baby, while he's still on the sewing machine. I thus attempted to collect the baby while he, in a husky voice, asked me to stop. Astonished, I halted. He stood up, came out, collected the baby and handed it to me. In a rather friendly manner, he said that he wouldn't allow me have a slightest body (i.e. hands) contact with his wife either.
There are thousands and one more similar stories to tell. I think all humans have tendency to feel jealous, especially of their spouses.
Jealousy in other places, or better, endeavours in life is strongly discouraged in Islam. It mounts to “hassada”, unbound/undue envy. This consumes one's good deeds as does fire to thatch.
We should therefore refrain from the latter, and do the former. Should you die in the protection of the virtues of your wife, Allah, the Exalted, promises you Heaven.