Isn't this a cultural difference in the US that's different from Europe, in that colleagues don't get involved?

The problem is that in the current #metoo environment, that would be taking a massive legal risk. Sweden recently passed a legislation that requires a proof of consent, or otherwise treats any sexual relationship as rape by default...

I have seen this a few times here on HN and it's just totally incorrect. The new law still places the burden of proving that consent was not given on the victim. Some papers reported it incorrectly but have published corrections.

First result on google: https://abcnews.go.com/International/wireStory/consent-law-r...

I don't have a view on whether this reflects the Swedish law correctly but if it does, I don't believe that changes anything nor that I am incorrect. Unless the other party established explicit, provable consent (he says-she says won't help in court), we are in absence of consent, and therefore rape territory. You can't prove absence of anything.

Colleagues get involved a lot, but it's often fraught/stigmatized--but not too much. Most Europeans I know feel similarly: it happens, but is a less-than-great idea for a lot of reasons, chief among them that if it goes badly you might still end up having to work closely with the person, or choose between them and the job.

It's extremely common, they just keep it quiet from HR. If they end up getting married it becomes known and is acceptable in the open.