OK, this is not that hard, people need to understand the rules.

First, the heuristics. If it would be extraordinarily awkward and/or conceivably career impacting for someone to decline a romantic advance then that advance should not be made, period, because it represents exploiting a power imbalance (even if unknowingly!) and throwing sex and romance into the situation. The only time in any scenario related to the workplace that romance or sex should see the light of day is if every party is fully empowered to decline with not even the slightest hint of impact to the workplace, career, employment, etc.

A good rule of thumb: unless a coworker is inarguably already a personal friend outside of work then introducing even the hint of romance into an otherwise entirely professional relationship could be not just awkward but potentially compromising. In every situation, the balance of doubt should always fall on the side of not engaging in romantic behavior with coworkers. Another good rule of thumb: if there is a level or authority imbalance (enormously more so if there is a direct superior/inferior relationship between two coworkers) then everyone should tread ten times or a hundred times more carefully than they would with any other relationship.

Whoever is making a move should be hyper conscious of any signs of discomfort on the part of the recipient and should go the extra mile (or ten miles) to provide many more easily available "outs" than normal. In normal dating situations if an advance is not welcomed that's fine, two peers had an interaction, someone made a minor mistake, and probably no one will get hurt. In a dating situation with all the complexities, minefields, and pitfalls of a work environment if an overture is made that is unwanted that almost certainly means that the person making it fucked up royally. They failed to read the other person, and they made them uncomfortable, and they complicated their professional relationship.

The 500 startups thing is a near perfect case of the sort of sexual harassment that many get away with because it has just the thinnest thread of deniability[1]. People should not be inviting themselves into the room or home of a coworker, period. People should not be trying to get cozy, let alone try to date, people they have only casually met, especially if there is a power imbalance between them or if there is absolutely anything at stake in the professional relationship.

If this sounds like a lot of restrictions, it is, but it's the only way to make sure that people feel safe and comfortable in their workplace and in their career. The workplace is not a dating service. If you happen to make a friendship at work that turns into a romance, congratulations, but that's not what it's for.

If the first, or only, thought you jump to when thinking about a workplace where romantic overtures are a lot more difficult is "that sucks, how are dudes even gonna get with any ladies ever?" instead of "it would be nice if we could get to a workplace that wasn't so toxic it kept hemorrhaging female talent by the day" then you are part of the problem.

[1] https://cherylyeoh.com/2017/07/03/shedding-light-on-the-blac...