I'd also add partners and gossip into the mix.

It's very easy for a third party to see a man and a woman having regular workplace relationship and associate that with flirtation and even cheating.

Of course this varies wildly in intensity depending on companies/partners, but it almost inevitably generates gossip. It's even worse if you're above her in the company hierarchy.

I know I would probably stray away from attempting this sort of work relationship with a woman for both my job and my partner's sake. It's a really thin line to navigate on both cases.

I've seen people get fired because a woman hinted that a man harassed her when I knew it was not the case.

But as said on another comment, this was true way before #metoo, that just brought even more visibility to this.