Being rejected sucks! Right? You don't get what you wanted. And you know what also sucks? Rejecting someone. You don't want to disappoint them, and you certainly don't want to incur their anger.
And so we avoid it by only asking for something when it's pretty certain that we will get it. This is locally convenient, but on a cultural level it is a slippery slope. Over time, it becomes expected for any request to be granted by default. This means that you as an asker have to make sure you don't ask for something that crosses the boundaries of the asked.
This is a problem because you (the asker) don't actually know their boundaries as well as they do.
There are false positives: the ask is too much, but the asked is too afraid or not vigilant enough to say no. They might be afraid that you will be offended if they say no, lashing out at them. Boundaries are crossed, and the asked is hurt. In some cases, the asker is shamed for being too forward.
There are false negatives: the asker thinks that their desire is too intimidating, and so never asks for it. An especially bad failure mode is when this makes them try to get the thing secretly. That's manipulation. You might think you never do this, but most manipulation happens without the manipulator even being aware of it. Most of it is subtle, and the only surefire way to remove it is to consciously address the need that the manipulation addresses subconsciously.
So how do we approach this problem? On one hand, the current equilibrium sounds like a Chesterton fence. We ought to investigate it before we decide to kick it down. On the other hand, the western tantric tradition has already changed it, and they seem to be doing fine. I suppose that this is one of these cases where we ought to swallow our pride and simply copy solutions of communities that have gone before us. Rationality is about doing whatever works.
The solution is simple: encourage a culture where the asked is responsible for their boundaries. Saying "no" should be encouraged and celebrated. Asking for whatever you desire, no matter how unreasonable, should be encouraged and celebrated. Entitlement, in the form of reacting negatively to a "no", should be strongly discouraged.
In this way, it is possible to always have complete common knowledge about the full extent of one another's desires and boundaries, opening up all kinds of opportunities for cooperation, and removing a lot of awkwardness.
So we practice. The rules of the game are simple. Taking turns, one person ask for something outrageous that they genuinely want. Like 50 euros or an hour-long massage. Then the other person answers honestly. They don't actually grant the request (maybe later). The point is to get used to getting the word out, and to practice getting a "no". Try and see how far you can take it!
Over time, players get used to the idea of asking people things, and begin to no longer fear rejection. Rejection therapy is sometimes cited as one of the most life-changing games one has ever played.
So for the next meetup, let's ask one another all kinds of outrageous things! And who knows; maybe we'll surprise each other.