VIDEO: Sneak Peek - 'Real Housewives' Luann De Lesseps Reveals 'Final Straw' in Her Marriage

Bravo Media looks to get the answers we've all been waiting for when Andy Cohen sits down with Luann de Lesseps at her refuge in Sag Harbor for a very special "Watch What Happens Live One-on-One with Luann de Lesseps." Airing Wednesday, September 6 at 11pm ET/PT, Luann will appear in a sit down interview for the first time since announcing her divorce. In the sneak peek below, De Lesseps reveals why she finally filed for divorce from her husband Tom.

Viewers witnessed the ups and downs between Luann and Tom play out on "The Real Housewives of New York City" for the past two seasons, but the couple sent shockwaves with the news they would be ending their marriage seven months after saying, "I do." Now Luann gets candid with Andy about the red flags she ignored, the rumors that questioned Tom's loyalty, and what ultimately led to the separation of New York's most talked about couple.

In addition, tune-in Wednesday, August 30 at 8PM ET/PT for "The Real Housewives of New York City" Part III reunion, when the housewives look back on their fun-filled trip to Mexico, from Lu's tipsy topple to the ladies' tequila-drinking marathon. However, the reunion takes a turn when Bethenny questions the sincerity of Ramona's tearful apology. In the hot seat, Ramona is forced to address the accusations she made against Bethenny this season.