She’s a total Betty.

Taylor Swift toasted Patrick Mahomes at his 30th birthday bash Monday night in a plaid set worthy of Cher Horowitz herself.

The pop superstar, 35, was photographed at the fête in Simkhai’s suiting-inspired Poppy vest and Payton wrap mini skirt — both of which sold out almost immediately.

She accessorized with sky-high burgundy Gucci platform heels and a sparkling Chanel pendant necklace, giving the schoolgirl classic a high-fashion twist.

Swift was joined by fiancé Travis Kelce, still in his Thom Browne shorts, along with Brittany Mahomes and guest of honor Patrick, at 1587 Prime steakhouse, the restaurant the Kansas City Chiefs’ stars co-own.

Despite the Chiefs’ loss to the Philadelphia Eagles on Sunday, the mood was all smiles. Country singer Kane Brown and his wife, Katelyn Brown, shared photos from the party, as well as a video of Mahomes blowing out a sparkler-topped cake as guests cheered him on.

The pattern has become a hallmark of the “Life of a Showgirl” songstress’ football season style, and her latest turn feels like a callback to some of her most memorable plaid moments.

Since she began dating Kelce in 2023, she has turned heads in tartan at Arrowhead Stadium on several occasions: There was the matching Vivienne Westwood corset and mini skirt, the businesslike Versace skirt suit, and the plaid pleated mini she paired with a gray Chiefs sweatshirt.

She also repped the print at last year’s VMAs — though the look was not, it turned out, the Reputation rerecording easter egg speculated by fans.