I'm just imagining Lehndorff finding out that totally unrelated people in the twenty-first century are reading and adoring his diaries! Would he be pleased or freaked out about that? I imagine a little of both?

The relationship with Heinrich ended in 1791 when Tauentzien switched from Heinrich's to FW2's personal entourage. (Chronology reminder:

Ahahaha. And here I had just replied to your earlier comment that Lehndorff, our sweetie, wouldn't suck up to the person with power over his beloved Heinrich. See, Heinrich, if you weren't so psychologically damaged you could have fallen for someone who truly and demonstrably cared about you! (Though I guess the count seems to have been better, so at least he had someone nice at the end, and I also suppose that Lehndorff may just not have been witty enough to be that person even if he was the nicest of all. One loves what one loves.)

I'd forgotten he was the boyfriend that made Heinrich watch the play with his brother! Heinrich really did pick the jerks, didn't he.

...are there other good stories from the Comte's wife about the Comte and Heinrich?

So he must have felt an attachment of whatever nature, and one that lasted through a life time, too

And that's true, too! My headcanon (do you think that if we all spammed Zeibura that she would tell us something about those letters? :) ) is that Heinrich couldn't ever really fall sexually for Lehndorff in the sense of finding him madly attractive unless he bodyswapped with Fontane but that he did really like him, perhaps found him relaxing (unlike his actual boyfriends!), and was happy to be friends (and occasionally friends-with-benefits) with him. In any case, I am glad that they had each other <3

And yet, he's still as passionately in love as that.

<3333333