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LeAnn Rimes is ticked off at accusations that her honey, Eddie Cibrian, betrayed her with another woman, despite the fact that she previously was the other woman.

In a Twitter blast on Wednesday, the country blonde, 27, railed against Star's new cover story, which alleges the so-called "dimpled hunk" cheated on her with his not-quite-ex-wife, Brandi Glanville.

She took particular exception to a follower who noted that "both of you did commit adultery so it's not far-fetched for anyone to believe that one of you would do it again."

Fumed Rimes, "You know what, who are you to be on your high horse? I've said truly and honestly that I'm sorry and I can't take it back. I wish everyone involved happiness, but EVIL actions and lies against anyone period is unwarranted."

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What's more, she said, "One day the truth will come out."

LeAnn then decided to prove just how schmoopily in love she and Eddie are by sharing a picture of them puckering up during a getaway this week to Montana.

"Going to LOCK MYSELF UP IN MY CABIN w/ @eddiecibrian, if you know what I mean," she wink-winked, nudge-nudged. "Nice dinner, amazing food. God, what a beautiful day!"

Judging by the volume of tweets Rimes has issued during their scenic, rumor mill-escaping retreat, it's a wonder she had time to notice anything beyond her keypad.

Cibrian, meanwhile, is directing his indignation at Glanville (aka the spouse he cheated on with LeAnn and then dumped).

Seems she doesn't deny Star's claims that they got up close and personal (or, as the tab puts it, "enjoyed passionate all-night sex sessions") soon after the actor went public with Rimes.

"LeAnn is getting a bitter taste of her own medicine," sneers a Brandi pal. "Eddie will keep cheating, because that's just what he does."

Cibrian, 37, who initially denied allegations that he was stepping out on Brandi with LeAnn, believes his estranged missus (and mother of their two sons) is bent on revenge.

"Once again my ex has stooped to a new low attempting to sabotage my beautiful relationship with LeAnn," he angrily tweeted. "Not surprisingly the ONLY magazine that decided to run the story shares the same credibility and delusion as my ex."

RELATED: Lots o' LeAnn photos

Chimed in a rep for LeAnn, "The Star magazine story is absolutely untrue and completely made up of lies fabricated by people who clearly have no lives of their own. LeAnn refuses to stoop to their level by acknowledging or responding to these ridiculous stories."

Others, however, are happy to stoop.

"LeAnn knew about it 100 percent," a Glanville source maintains to E! News of the purported hookup. "Obviously, she was upset. Eddie and Brandi were intimate after he and LeAnn were together, but it only happened twice."

Cibrian recently began cohabitating with Rimes, a move they made not long after her ex-husband, Dean Sheremet, confirmed that he was shacking up with his girlfriend.

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