A gentlemen never kisses and tells — but then again, Justin Bieber isn’t your typical “gentleman”!

Just a few weeks after it was reported that Kourtney Kardashian, 36, rebounded by hooking up with the singer, 21, a source says he’s “bragging” about their ~fling~ to his pals!

RELATED: Kourtney Kardashian Steps Out With Another Young Man Amidst Justin Bieber Dating Rumors!

kourtney and justin

“Justin bragged to friends recently that he has been hooking up with Kourtney Kardashian,” an insider tells Us Weekly. “That’s definitely happening and has been for some time now. Every time Kourtney and Justin are together, they’re extremely flirtatious. They text each other all the time.”

Neither Justin nor Kourtney has directly addressed the rumored romance — though it was previously suspected that the Biebs poked fun at Kourt’s baby daddy, Scott Disick, on Instagram.

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Lord knows

A post shared by Justin Bieber (@justinbieber) on

Hours after their alleged initial hookup, the “Sorry” singer posted the above Instagram photo, which he captioned, “Lord knows” — possibly alluding to the 32-year-old dad's self-imposed title of “Lord Disick.”