After the Time article on sexual harassment and abuse within Effective Altruism and Owen Cotton-Barratt's resignation there's been a lot of discussion around the extent to which EA culture did or didn't contribute. This has included proposals that EA try to be more conventional, such as discouraging polyamory or hookups within the community. At which point others naturally bristle: what happens between consenting adults is no one else's business, and it's wrong to try and influence others here. For example:

I don't see any way you could meaningfully "address" the work/social overlap without trying to get people not to date, live with or befriend people they otherwise would have dated, lived with, or befriended. And if you put it in those terms, it seems messed up, right?

Or:

I will not be a part of community which treats conscious and consensual behavior of adult people as their business.

Or:

Perhaps consider minding your own business about whether or not consenting adults sleep together.

Now, the people who wrote these have more nuanced views than these quotes suggest, and I think we don't actually disagree much when it comes to views on detailed situations. Still, I think it's worth getting some of that nuance out there.

Specifically, consent isn't always enough. Even consent plus a mature awareness of power dynamics isn't always enough. Consider a case of someone whose job it is to direct funding for a foundation sleeping with one of the people who runs an organization they might recommend funding. And let's further imagine that the grantmaker and grantee both have a sophisticated understanding of power dynamics, great communication, solid introspection, strong self-confidence, and the best of intentions. Even then, this has corrosive effects on the community, including:

Other grantees would then feel pressure to sleep with grantmakers, leading to bad interactions, including ones where all the signals that the grantmaker receives are that the grantee wants this.
The funders behind the grantmaker may reasonably worry that the grantmaker's judgement is clouded by their otherwise positive views towards this grantee or that there was quid pro quo.
People with unsavory intentions may choose to become grantmakers because a norm of "it's ok to sleep with grantees" is very vulnerable to abuse.

These are harmful enough that we can't leave it to the couple to determine whether their roles as grantmaker/grantee and lovers are compatible. That sometimes someone's role conflicts with a relationship they would like to have is unfortunate, but not always avoidable and not unique to this case: other examples of romantic relationships with similar issues include ones between managers and their reports or professors and their students.

Organizations handle these conflicts in a range of ways, often depending on how they think about the effects of these relationships on others and whether they can satisfactorily mitigate the professional consequences of a particular relationship. For example:

A university might consider the initiation of any relationships between students and professors to have a harmful effect on their culture, and that students should be able to trust that professors are interested in them only academically. If they prohibit them, a professor would need to choose between avoiding such relationships and resigning their post.
A large funder might require disclosure and recusal: when a relationship relevant to a grantmaker's work comes up they work with their manager to transfer responsibilities so that the grantmaker is no longer influencing outcomes for the grantee. This is also how larger organizations usually handle employee relationships that interact with formal power.
A small funder might not be able to do this, perhaps because they only have one grantmaker in an area. Options for handling this could include committing not to fund the relevant organization, the grantmaker leaving, or the grantmaker passing up the relationship. All of these have significant downsides. Smaller organizations, or specialized departments within larger organizations, can have similar issues that would keep them from being able to mitigate the effects of an employee relationship.

There are also other areas where we accept people have a valid interest in discouraging some kinds of consensual interpersonal behavior, where power dynamics and conflicts of interest are not the concerns. For example, norms against cheating in relationships, sleeping with your bandmates, or hookups within a military unit.

As I wrote above, I don't think this is especially controversial. But it shows that the question is what norms we should have and not whether it is legitimate to have norms beyond consent. This is the approach we need when considering the actually controversial cases.

On the more specific question of what norms to have, I don't know. This requires weighing harms like the departure of people frustrated by excessive romantic attention, abuse of ambiguous power, loving relationships that don't happen, exclusion of unconventional thinkers, and delay in ejecting jerks. I think the discussion has shown both that we didn't have much agreement on what norms we'd been operating under and that we have a wide range of opinion on what's reasonable behavior. I'm hoping we can get closer to figuring out what sort of norms would best make a thriving community that supports all of us in making the world better.

Disclosure: my wife is on the Community Health Team at the Centre for Effective Altruism. I haven't run this post by her and don't know her views.