What the HECK?!

Kim Kardashian appears to have met up with sis Khloe's baby daddy Tristan Thompson at a NY restaurant last night because ... did they both really end up there AT THE SAME TIME, coincidentally?!

We call BS on that -- in fact, Us Weekly claims a social media user uploaded a pic of the two sitting right next to each other at Estiatorio Milos in NYC, though the outlet doesn't name the Insta-account and we can't seem to find it. Meanwhile, DailyMail says the two "almost had an awkward run-in." So which is it?

All we know is Kim, who was also dining with besties La La Anthony, Jonathan Cheban, and publicist Simon Huck, was wearing a super-see-through halter top -- not unlike the silvery number she wore earlier the day before. And again, black leather pants -- probably the same ones. Maybe she needs a bigger suitcase?!

But back to the issue at hand ... wouldn't you be PISSED if you were Khloe?