Amid a longstanding feud with Miley Cyrus, Selena Gomez allegedly had a one-night stand with her enemy's ex-fiancé, Liam Hemsworth, last year.

According to Life & Style, via HollywoodLife.com, Gomez was "absolutely furious" to find out that on-again, off-again boyfriend Justin Bieber and Cyrus had a brief fling back in 2012 when they were on a break.

Seeking revenge against Cyrus, the "I Want You to Know" singer allegedly hooked up with "The Hunger Games" actor in the summer of 2014.

"[Hemsworth] bragged about it to his friends," a source revealed. "It was just a one-night stand, but Miley had no idea!"

Since the "Wrecking Ball" hitmaker supposedly "hates Selena more than anyone in Hollywood and Liam knows that," she considers the pair's alleged affair "a huge slap in the face."

"If Liam really did hook up with Selena, it will be devastating," a source told HollywoodLife.com. "She doesn't care who he sleeps with, but Selena is the one exception to the rule."

The source added that Cyrus is not just going to let it go. Cyrus will reportedly confront him about the alleged hookup.

In addition, while Gomez is romantically linked to rumored new boyfriend Zedd, her ex is reportedly in a "friends with benefits" relationship with Kendall Jenner.

Bieber and Jenner recently showed off PDA at this year's Coachella Valley Music and Arts Festival.

A HollywoodLife.com source seems to believe that though Jenner and Bieber tell people they are friends, they are more than that. Their comments are supposed to be all about throwing people off.

Similarly, In Touch recently reported that the two have secretly been hooking up for weeks. At a Clippers game, a source reports the two were being affectionate with one another. Bieber gave her kisses on the cheeks and touched her leg during the March 20 game. The very public venue was their choice for the "secret date."