Views on emotional cheating vs casual physical encounter with no emotions

I’m married having a good marriage overall, but something has been on my mind lately and I’d love to hear your perspectives. When I was a teenager, it was commonly believed that physical intimacy before marriage was unethical and outside of marriage was considered one of the worst things you could do "biggest sin." But as I’ve grown older, societal perceptions seem to have shifted. Nowadays, I see more people discussing emotional isolation in relationships, saying emotional support is often lacking. At the same time some people seem to treat casual intimacy as more acceptable if emotional intimacy is absent. Is it okay for a partner in a marriage to seek casual physical intimacy if there’s no emotional attachment involved?