It's hard after so much time but this sounds like it's just escalating
Was he using you in grade/high school as a human shield? That sounds cold but how long ago do you think the using really started?
And he's also blurted out your business more than once publicly. Maybe in high school you might've thought it was to protect both of you (or maybe especially him?
Since you then apparently had to live up to that tougher rep,
----unless you'd have been tested by bullies anyway and his statements were truly for mutual protection?
)
But to announce something very embarrassing & private (anyone can be overcome by a drugged drink, for example, and I'm not looking for more info, that was just enough to make your point --- just so you realize you shouldn't be embarrassed, but that was
really private information that he "outed"
)
...that he blurted out in front of your
date 
Was
HE trying to steal YOURS?
Sounds like he's worried about your innocent behavior with his date because he himself has no honor
(and really, obviously his dates WERE better off with you or your other friend any day....
)
What a bad joke,
the man has to pay, he actually
said that to you after getting you to pay for his date with a woman???
(He can't complain about your taking over his role with his date since you paid for their evening out anyway
😛 according to his "logic". Especially since regardless of money, you're the gentleman, you waited to be sure his date/s got home safely!!)
----Even aside from spending his money in *front of you after manipulating you out of yours, and for so long
(and trying to screw up your date/s while making you pay for his
)
----I think the total disregard for your feelings alone, trying to humiliate you publicly to make himself look witty at HUGE cost to you
tells you this is no friend ----
(And he'd get you in trouble at school with bullies when younger? Just more of the same as an adult, causing a public situation you'd have to pay for one way or another?)
And then the lies on
Facebook, which can reach everyone you know, is again
more public abuse & manipulation, on an even bigger scale,
now he's also trying to tarnish your reputation with lies?!
(Maybe that's because he assumes you'll tell the truth about him, just because he doesn't have the honor or decency to keep his mouth shut about
*your business...
--so he went on the offensive to fix it so he'd come out looking good at your expense again)
Thankfully many others see through that, which might be another reason he might want to reconcile ----
his latest & biggest attempt at
your public humiliation for
his benefit backfired in a big way.
"A friend in need is a friend indeed" Sounds trite & cold but sometimes it's hard to distinguish, though here there seems to be no question this guy is bad news.
Any one of the above would be enough of a reason to sever ties with someone, especially when the abuse is repeated, and increased.
After so many years & shared experiences it's very, very hard to be objective, but at least you seem to see that his behavior is destructive, and not just to you.
He's obviously not a friend to you (such a user shouldn't be in any relationship).
It sounds like at least one massive character flaw, and it doesn't sound like he'll easily "grow out of it". Good idea to have at least the other friend with you when meeting him. You might be doing him a favor by telling him off directly, but then again he probably knows what he's doing wrong, and just needs to know he can't get away with it.
Severing ties permanently, you help yourself and him both, he *might take other people more seriously in the future if he realizes this crap will cause him to lose friends.
Regardless, he's abusive, that's enough reason to be done with it.
