Nobody said it was OK. It's dubious to call it a threat.

It's not at all that dubious. Threatening to "shred her hymen" is, well, a threat. Curt didn't know this guy, and he's a father who just had someone tell them they want to rape his daughter. I'd consider that a threat too.

Amid comments that imply she wants the(ir) D, that comment says she'll be slutting around with him, first.

Completely irrelevant. If you told me that my daughter was "slutting around", then I'd assume she was being forced. I'd be even more likely to consider you a rapist.

What makes something a threat or not is not the conclusions the recipient of the message jumps to.

Wrong. You might want to look at ''Elonis v. United States'' [1].

1. https://en.m.wikipedia.org/wiki/Elonis_v._United_States

Not wrong, because the case you linked does not conclude that what constitutes a threat (even in this legal sense) is what the recipient of the message believes.

It did conclude that it was a threat, and amongst the finer points of the case was that Elonis argued that the test should have been whether he intended the threats or not. The jury decided that a reasonable person would have perceived the accused comments were threatening.

Even a reading of a cursory summary of this case would have told you this. Did you actually read the outcome?

What. How does your reply have any logical connection to what I wrote?

I just showed you a case where a threat constituted the conclusions the recipient jumped to. Do try to keep up.