It is only "cringe" if you read it as a genuine attempt at cybersex, which it clearly is not.
If you read it with a large pinch of salt, as intended, it is in equal measures funny and informative, which makes it immediately better than 95% of posts.
It's cringe because some old dude creeping on what he thought was an extremely young women. It's even more cringe when you learn it turns out the creepy old dude was actually fooled by a 15 yr old boy... It's just gets plain sad when the old dude takes so long to figure out he was a mark all along.
Fair points. Perhaps I'm just naive assuming it was all a big joke. Surely people don't seriously try to chat people up using cryptography metaphors, especially someone clearly intelligent like Nullius?