Another one! Tristan Thompson can't seem to help himself from dropping flirty comments on ex Khloe Kardashian's Instagrams -- he's done it twice recently.

We've all had that boyfriend who messes up but keeps trying to reel you back in even though you swear you're done with him ... well this is that, times 100! Khloe and Tristan's messy, very public breakup after the father of her child cheated on her with family friend Jordyn Woods made headlines for weeks. Everyone's pretty much in agreement that Tristan's a dirty dog and Khloe should stay away romantically, while still rising to the co-parenting occasion for the former couple's daughter True.

But Tristan seems to want to have it both way ... you KNOW the NBA'er isn't planning on being monogamous anytime soon, yet he keeps trying to hold on to Khloe -- probably so he can get some when he's in LA visiting his daughter and his son Prince with Jordan Craig. And maybe he's gettin' some from her, too!

So Khloe posted a new inspirational selfie today captioned, " May you have the courage to explore every dream you dream." Okaaaay, and Tristan wrote, in a new deleted comment: "The sun is shinning bright on a beautiful 💎"

The other day, Tristan commented on Khloe's NUDE selfie, in promotion of a Poosh playlist for Kourtney, writing, "Perfection" under the sexy shot. He deleted that one, too ... just to make Khloe CRAZY!