Over! The relationship you didn't even know was happening is finished and ... if a tree falls in the forest and no one's around to hear it, does it make a sound???

Kendall Jenner and her Australian Philadelphia 76ers basketball boyfriend have called it quits right after Vogue Australia interviewed the young model and had her talk about her "private" and "sacred" relationship with her man and possibly MARRYING him one day. Oops! That's what happens in a 24-hour news cycle, folks -- sit down with Vogue in April, do the photo shoot in May, magazine writes it up, edits, it, lays it out, sends it to the printer, ships it out and BAM! You've got old news.

Anyway, word is now, the two have called it off. A source tells Us Weekly: "It wasn’t so sudden. Things have wound down between them. They aren’t seeing each other anymore ... They were getting serious for a bit, but were starting to cool off recently. They’re so busy doing their own things and realize they’re young and want to have fun."

They supposedly split in Sept 2018 after just four months of dating and then reconciled some time after that. But the two were never very public with their romance and probably didn't see each other that much with bi-costal lives and with Kendall's crazy modeling schedule. So basically ... over before it began!