Over what could loosely be described as my professional career I have encountered the following situations (European also includes Britain):
1. A lead engineer in a giant European company reporting directly to his long-term partner, who was in a very senior position.
2. An HR manager in a smallish European/American/Russian JV reporting directly to her husband, who was the company General Director. When an employee had a serious row with her over his terms and conditions, it was escalated to her husband for arbitration.
3. A lead engineer in a giant European company reporting directly to her husband, who was in a reasonably senior position.
4. A woman working in a giant European company who was tasked with managing a subcontractor on behalf of her husband, who was the actual contract holder. Any disputes between the subcontractor and her would be escalated to her husband to resolve.
5. A very senior site manager working overseas for a giant European company got his (local) secretary pregnant. He sent his family back home and moved his new mistress into his company-provided house. His boss couldn’t complain too much because he’d done much the same thing several years earlier.
6. A lead engineer working in a large European company embarked on a relationship with one of his trainee engineers, who was about 30 years his junior.
All of the above situations were not only allowed to continue, but some were even known at the outset. The excuse given was that the company had to find positions for both partners and this was difficult at the best of times. Others didn’t want to lose an experienced staff member, so turned a blind eye.
By contrast, I once met a man working for ExxonMobil who managed a team of translators and began a relationship with one of his direct reports. They declared the relationship in short order and they were told one of them would have to resign. The woman got a job elsewhere, they married, and had kids.
It is perhaps significant that all of these happened outside the country where the respective companies were based. Whether this is also permitted in their HQ I don’t know. What this taught me is that a lot of management is simply individuals doing whatever is most convenient to them at the time, principles and ethics be damned. The Americans seem to be a little more professional in this regard, and I don’t think it comes as a surprise that the sole exception came from ExxonMobil.
For my part, I was told early in my career never to “poke the payroll”. It was good advice.