Jessica Simpson stars in new Chicken of the Sea ad — 20 years after 'Newlyweds' flub. She's long been in on the joke.

It's a full circle moment for Jessica Simpson as she revisits her infamous, on-air tuna gaffe — with 11-year-old daughter, Maxwell Johnson, by her side — in a new ad for Chicken of the Sea.

Twenty years after the singer/reality star/fashion mogul questioned whether she was eating tuna or chicken on Newlyweds: Nick & Jessica, a breakout moment that catapulted her to pop culture stardom and drew exasperation from then-husband Nick Lachey, she gamely revisits the topic for a brand campaign — and presumably fat paycheck.

In the spot, Maxwell asks what she's eating from the pouch and Simpson explains, "It's called Chicken of the Sea, but it's not really chicken. It's tuna, so don't get confused by it." Her daughter replies, "Who would ever get confused by that?!" Simpson replies, "No one? Not your mom."

A second clip sees Maxwell asking the question Simpson posed to Lachey when they were documenting married life for MTV in 2003: "Is that tuna or chicken?" When Jessica replies that it is confusing, the sage tweenager shoots back, "I'm joking. I know it's tuna." An embarrassed Jessica says, "Oh, me too." Simpson wrote that she's"still a @chickenoftheseaofficial gal" all these years later, as she shared a clip to social media.

While many stars would have distanced themselves from the original TV faux pas, putting it at the top of their publicist's list of banned topics, Simpson — just 23 with big pop star ambitions — leaned into the bubblehead blond persona. While, yes, it was a "legitimate ditzy moment" — along with the Buffalo wings and "plata-ma-pus" mistakes — she acknowledged in her 2020 memoir Open Book that she "didn't care if people made fun of me because we were pulling in nearly three million viewers a week" and selling her albums after she had been dismissed as a "Britney [Spears]-bot."

She wrote, "Somehow I was always the joke. Everybody made fun of something I'd say, and I'll admit I definitely played into it. People's laughter meant a lot to me, and being the joke validated me being smart to myself. It felt like I could pull one over on somebody. I thought: How dumb are you to think I'm that stupid."

Not long after Simpson uttered those lines in the Aug. 19, 2003, premiere of Newlyweds — "Is this chicken, what I have, or is this fish? I know it's tuna but it says Chicken by the Sea. Is that stupid?" as she ate the Atkins-approved dish on her couch — she released a music video for "With You" in October 2003, in which she was ... eating tuna. The video quickly became an instant hit on TRL.

The same month, Rolling Stone's newly minted "Housewife of the Year" appeared at a Chicken of the Sea company conference, where she was educated about the product. Simpson was paid what she called "crazy money" to be there and left with a giant gift basket of products. After all, her TV tuna questioning had helped raise sales of Chicken of the Sea by 10 percent. She was "in talks" to become its new spokeswoman, but that apparently didn't pan out for another 20 years.

Instead, she went on Saturday Night Live and joked about tuna in 2004.

Simpson — who divorced Lachey in 2005 — has kept it going for a long time. She's shared memes, including this one of a chicken swimming: "Maybe Jessica Simpson was on to something?"

When Whole Foods had a tuna scandal in 2017 — the supermarket chain had mislabeled tuna, which found its way into the buffalo chicken salad — Simpson shared an A+ tweet: "It happens to the best of us @wholefoods."

A few years later, Subway faced a lawsuit over its tuna, and she put in her 2 cents: "It's OK @Subway. It IS confusing."

In her 2020 bestselling memoir, she said she semi-entertained tuna-chicken titles for the book. While brainstorming titles with girlfriends, one suggested calling it, "'I Know It's Chicken.'" To which she replied, "'Guys, it's tuna. I should know'" and they all had a laugh. She went with Open Book because it covered so much more than the viral moment that launched her career (and made her a much bigger star than Lachey, fracturing their relationship) — including her divorce, alcoholism, toxic relationship with John Mayer, nearly dying from plastic surgery and more.

Even last year — the same year Newlyweds turned 20 — she had fun with the reference as she posed in front of a mural with chicken legs. "Are these wings pig or chicken?" she asked her Instagram followers.

And now ... she's fully revisiting tuna-gate in the funny ad alongside her firstborn. Once again, she doesn't mind being the stooge to the savvy young daughter, whom she shares with husband Eric Johnson, for the bit.

Simpson and Johnson — married since 2014 — are also parents to Ace, 10, and Birdie, 4. Maybe the next ad will feature the whole fam, because you know Simpson's not done joking about tuna yet.