Tom gets slammed by son’s ex-GF Xenu hating dad.

CONNOR CRUISE’s romance with “Walking Dead” actress Alanna Masterson is DOA, disappointing his superstar dad Tom – but the 19-year-old DJ has already rebounded with a hot-looking blonde!

Connor, who was adopted by Tom and Nicole Kidman during their 10-year marriage, was photographed frolicking in the sea with the mystery beauty at the grand opening of the Hard Rock Hotel Riviera Maya in Mexico recently.

He’s also bulked up considerably, which sources say may be due to a party-hearty lifestyle.

“He was even photographed smoking a cigarette, which probably won’t please his squeaky-clean dad,” noted an insider. “For Tom, Connor’s partying lifestyle and weight gain have got to be huge red flags.”

Cruise is also said to be unhappy that Connor’s relationship with Alanna went belly-up.

The 25-year-old actress, who plays emotionally fragile zombie-fighter Tara Chambler on the hit AMC show – is a dedicated Scientologist. And the insider says the “Top Gun” hunk had given the relationship “his seal of approval.”

But the romance exploded after Alanna’s father, former Australian rugby star Joe Reaiche, declared flat-out: “Connor is the worst person in the world for her to date.”

Reaiche left Scientology in 2005 and has since spoken out publicly against the controversial church – and Cruise.

“I call Tom the Prince of Darkness…and I don’t want my daughter anywhere near him,” Reaiche fumed.

Added the insider: “Tom thought Alanna would be a good influence on Connor and they would become Scientology’s new power couple, but now he’s got to be wondering what the future will hold for his son.”