It seems for some people, immediate blocking is their preferred way of saying, “I no longer want to meet in the future.” Call me judgmental if you want, but that’s a cowardly act if you ask me. It’s passive aggressive; it’s accusatory; it’s hostile; and it’s rather dehumanizing as well. It’s also riddled with assumptions. If you block someone immediately, before any negative exchange had occurred, then you are likely assuming the person is unsafe. You are either assuming that it is dangerous to tell the person that you are no longer interested in meeting, or you don’t have any such fears and you just want to make the person feel bad. Either way, it’s very hurtful and at least somewhat intentionally so.
These people typically don’t show any obvious sign that anything is wrong. They will pretend to have enjoyed the experience. They will pretend to have been happy afterward. And they will pretend to leave you on good terms. But if they then proceed to block you as soon as they get home, there’s no way they could have honestly parted with you on good terms. In general, in order to provoke a blocking, something seriously wrong should have happened. I would think simply “not being satisfied” would not be enough to provoke a blocking. Because in that case, a blocking is more like flipping a middle finger than a defensive act.
I could only surmise, it could be that the other person was uncomfortable with something, such as a certain cuddle position. And it could be potentially anything that they may have been uncomfortable with, not necessarily a certain position. It could be a smell; it could be the other’s height, voice, or appearance in general. It could be anything. But they failed to voice it at the time. They pretended to be comfortable the entire time. Then after the session, their anger at putting up with something that made them uncomfortable boils over, and they act it out by blocking. That’s just a hypothesis. Or it could be that nothing in particular made them uncomfortable, it could be they just didn’t enjoy the experience enough to want to meet again, which if anything is an even stranger reason for a blocking. But either way, it’s very shitty behavior to appear to part with someone on good terms, then send the latter home to find that they had been immediately blocked.