LuAnn De Lesseps' estranged husband, Tom D'Agostino, wasted no time moving on from their relationship. In fact, according to a shocking new report, D'Agostino is newly engaged.

Just over one month after the Real Housewives of New York City star announced to her fans and followers on Twitter that she and D'Agostino had decided to call it quits after just seven months of marriage, D'Agostino has stepped out with De Lesseps' "worst enemy," Anna Rothschild.

“Tom gave Anna a huge diamond ring,” a source close to the couple told Radar Online on September 9.

De Lesseps and D'Agostino tied the knot on December 31, 2016 after he was faced with weeks of allegations regarding his potential cheating. Then, on August 3, 2017, they filed for divorce and he quickly moved on with another woman.

“They’re very in love,” the friend said about D'Agostino's new relationship with Rothschild. “This is the real thing.”

News of D'Agostino's relationship with Rothschild was first reported after he was seen with his new love in The Hamptons during Labor Day weekend.

“Anna has been friends with Tom for 12 years,” an insider told Radar. “She hates Luann!”

Last week, De Lesseps opened up to Andy Cohen during a late-night Watch What Happens Live special about the end of her marriage to D'Agostino.

“I had that moment of ‘Oh my god,’ I had these blinders and all of a sudden they came off,” she said. “I thought, ‘This is not good.'”

She then admitted that the end of her marriage wasn't completely the fault of D'Agostino.

“Listen you can’t blame [Tom] 100 percent, it was a bad situation that couldn’t get better … life takes care of itself,” she said.