In the end, Luann de Lesseps couldn't make her marriage work.

After tying the knot with Tom D'Agostino on New Year's Eve, the Real Housewives of New York City star announced via Twitter Thursday that they mutually decided to end their seven-month union. "It's with great sadness that Tom & I agreed to divorce," the 52-year-old reality star wrote. "We care for each other very much, hope you respect our privacy during this sad time!"

A source tells E! News that Luann's co-stars had no clue that the couple would be filing for divorce today. "Everyone is surprised by the announcement but not shocked by the news," the source says, adding that Luann's friends "had been encouraging her to get out of the marriage."

Bethenny Frankel, who confronted Luann about Tom's alleged infidelity last season, was asked about the couple's marital issues during an appearance on Watch What Happens Live With Andy Cohen Wednesday. "I really feel badly for her, because she's been living this totally out loud. I think it's personal," she said. "They got married and I decided to stay out of it after that."

After Luann announced her divorce plans Thursday, several cast members offered their support. "I told Luann I'm there for her whether this worked out or not and here I am. Men come and go, and at the end the day, we have our girlfriends, don't we?" Sonja Morgan told E! News in an exclusive statement. "I wanted it to work out, but I want her to know I'm here for her." Similarly, in an exclusive statement to E! News, co-star Ramona Singer said, "My heart breaks for her. Luann went into this wanting to make it work. I've never seen her happier."

Dorinda Medley, the sole cast member to attend their wedding, also shared her sympathies. "It's always sad when a marriage doesn't work out," she said. "I wish the best for both of them."
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