No word on who the mystery dude is ... or how they know each other ... but as long as he's not a married country singer with two kids at home, shouldn't be a problem.
TMZ obtained pics of the former "American Idol" contestant ragin' with Grubbs at a bar earlier this year -- and sources connected to the ladies tell us they've been friends for a while.
We're told the two initially met while working together at an L.A. bar ... and hit it off.
Of course, Grubbs shot to fame when it was revealed she was one of a bazillion women Tiger was nailin' behind his wife's back.
These days, Grubbs is still screwing around with a married man -- her brand new husband.
The cyber-hate came flooding in after TMZ posted the pics of Aldean -- a huge country singer who happens to be MARRIED -- putting the moves on Kerr at a crowded bar on the Sunset Strip.
Sources connected to Kerr tell us ... she had NO IDEA Aldean was married ... and if she would have known, she would have shut the whole thing down from the start.
Even though Kerr didn't go home with Aldean, people attacked her online ... writing terrible things on her Facebook page including:
"Disgusting homewrecking tramp!"
"what is wrong with you taking advantage of a married man while he was drinking."
"everyone thinks ur a slut!"For the record, people have ripped Aldean on his Facebook page too. He has since apologized, chalking the whole thing up to a bad drunken decision.
We reached out to Kerr -- so far, no comment. See More: Jason Aldean , Brittany Kerr , Music , 8 More Photo Galleries , Jason Aldean & Brittany Kerr Cheating Scandal , American Idol , Facebook , Exclusive , Celebrity Justice , Paparazzi Photo , Hook Ups Hide these
