Lord Disick spilled the beans Friday when he commented on Khloe's bikini pic on Instagram and wrote, "@realtristan13 is a lucky man!" But, Scott must have quickly realized he spilled the beans ... because he was quick to delete it.

As we reported ... Khloe and Tristan have hung out a lot in recent months and they've been quarantining together off and on since the lockdown. She and the rest of the fam also headed to his pad in L.A. to celebrate on the Fourth of July weekend.

Tristan's been hanging out with Khloe and her fam for a bit now ... all but indicating they had given their relationship another go-around.

Tristan, for his part, has more than professed his love for Khloe as of late. They do share a daughter, True, and for a while now it sure has seemed like they've been doing more than just co-parenting.