"Scandal" fans have already realized that First Lady Mellie Grant (Bellamy Young) isn't exactly just an innocent, pregnant accessory on the Presiden't arm ... she seems to be an accessory to quite a few crimes. And she's not alone.

Along with Chief of Staff Cyrus Beene (Jeff Perry), some very high-up government leaders and her nemesis -- a.k.a. her husband's former mistress -- Olivia Pope (Kerry Washington), Mellie has been privy to quite a few scandals of her own.

We've got an exclusive sneak peek at this week's episode, titled "Defiance" (Thurs., Nov. 29, 10 p.m. ET on ABC), which finds the First Lady more than a little hesitant to go to the President's (Tony Goldwyn) 50th birthday party -- a party she planned and insisted on having.

But the President's not buying her sweet pleas. At all. He shuts her down with one very loaded statement: "We can't always get what we want, can we?" But is he walking into a firestorm bigger than wife vs. mistress? Watch the clip above to see.

Tell us: What do you think is making Mellie so anxious? And are Fitz and Olivia really over, like the president says?

"Scandal" airs Thursdays, 10 p.m. ET on ABC.

Here's ABC's official description for this episode: "Defiance" - Harrison leads the team in managing a billionaire businessman who seems to have lost his sanity; meanwhile, Olivia and the White House prepare to celebrate the President's 50th birthday, as James continues to investigate Cytron and discovers something that could change the fate of the country.

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