Time to pay the piper! Luann de Lesseps is furious during a phone conversation with fiancé Tom D'Agostino Jr. over infidelity rumors in The Real Housewives of New York City's season 8 finale on Wednesday, August 24, as seen in Us Weekly's exclusive sneak peek.

The Bravo series' first-look clip centers on the countess getting heated in the chat with her man while Bethenny Frankel listens from the bed. Frankel, 45, finally approached de Lesseps, 51, at the end of last week's episode about pics that appear to show the businessman making out with another woman at the Regency Hotel in New York City.

"Bethenny just sent me the picture, Tom!" de Lesseps tells him through the phone in the preview scene. "You have no recollection? What does that mean? You were so wasted you don't remember?"

"How could do this to me — at the Regency, in front of everybody!" the reality TV mainstay continues. "How can you do this?"

When D'Agostino Jr. tries to tell his side of the story, his fiancée fires back, "She was giving you a kiss? You were making out for an hour!"

A previously released promo for the episode revealed Frankel's dismay at de Lesseps' concern about the public nature of Tom's kiss. "I'd be focusing on the betrayal," the Skinnygirl mogul told the camera in the finale's trailer.

De Lesseps and D'Agostino Jr. are planning to tie the knot on New Year's Eve, and she recently told Us exclusively that she is waiting until after the RHONY reunion airs to decide which costars to invite to the nuptials.

Watch the tense clip in the video above. 

The Real Housewives of New York City airs on Bravo Wednesdays at 9 p.m. ET. 

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