Miley Cyrus and Liam Hemsworth have hit a rough patch over cheating allegations.

Miley Cyrus and Liam Hemsworth have hit a rough patch over cheating allegations. (Photo: INFDaily)

Miley Cyrus’s dad, Billy Ray Cyrus, who was all for her engagement to Aussie boyfriend Liam Hemsworth, has reportedly had a change of heart since rumors of Hemsworth’s cheating scandal with “Mad Men” hottie January Jones.

It hardly seems possible. Only last November, Billy Ray said he couldn’t wait for Miley to walk down the aisle.

The 20-year-old actress and Hemsworth, 22, became engaged in June a year ago after dating for three years. They met on the set of Miley’s movie “The Last Song.” But Billy now wants their relationship to be a swan song before Miley’s heart goes achy breaky.

All the usual Hollywood excuses are being cited. Billy Ray was reportedly upset by rumors that Liam cheated on Miley with Jones. And, he was supposedly concerned that Liam was using Miley to boost his career. But that’s a laugh.

If anything, it’s the other way around. Hemsworth is one of the hottest actors in Young Hollywood, following his breakout role in “The Hunger Games.”

And who’s using who? “Liam asked if he could have my daughter’s hand in marriage, and I said ‘yes,’ if I could be in his brother’s next movie,” Cyrus half-joked to USWeekly. He was referring to “Thor” actor Chris Hemsworth.

Billy reportedly sees the handwriting on the wall, according to The National Enquirer.

“He’s fed up with the disrespectful way Liam treats Miley by constantly flirting with other women in front of her,” a source told the tabloid. “He’s had deep reservations about Liam from the start, because when Miley hooked up with him, she was the big star and he was an unknown in America.”

Trouble started brewing when Hemsworth was spotted with “Mad Men” hottie Jones flirting madly at a pre-Oscars party. Shortly afterward, Liam flew to Australia, but returned to LA in March and the two appeared to have put their differences behind them.

Still, at 20, she seems waaay too young to get married. Stick with TheImproper on Twitter for all the latest Miley Cyrus updates.