KANSAS CITY, Missouri (WCMH) — Everyone knows about the budding relationship between Taylor Swift and Travis Kelce, but there was another budding relationship for the pop singer on display during Sunday’s game between the Kansas City Chiefs and Los Angeles Chargers.

Swift and Brittany Mahomes, the wife of Chiefs quarterback Patrick Mahomes, were caught on camera late in the first quarter performing a secret handshake/hip bump in one of the luxury boxes of Arrowhead Stadium. The NFL tweeted a video of the handshake, captioning it, “Not the handshake!!”

And there was good reason to celebrate — after ending the first quarter tied 3-3, the Chiefs put 7 on the board early in the second on a 46-yard pass to Marquez Valdes-Scantling, which prompted the celebration.

The Chiefs went on to put away the Chargers 31-17.

In addition to Sunday’s celebratory handshake, Swift was seen wearing a friendship bracelet with “87” — Kelce’s jersey — on it.

Kelce finished the game with 179 yards (his second most ever in one game), 12 catches to match a career high, and the 50th Mahomes-to-Kelce touchdown.

Rumors of the Swift-Kelce pairing started swirling earlier this summer when Kelce said on his podcast that he tried to get Swift his phone number during the Kansas City stop of her “The Eras Tour” in early July. Kelce’s brother Jason seemingly confirmed the relationship during a radio appearance on Sept. 20.

Swift, at Kelce’s invitation, attended her first Chiefs game on Sept. 24, a 41-10 drumming of the Chicago Bears. Since then, she’s been to three other games — Oct. 1 against the New York Jets, Oct. 12 against the Denver Broncos, and Sunday’s Chargers’ game.

Chiefs fans shouldn’t be too mad about the attention the relationship is getting — starting with a Sept. 17 win against the Jaguars, the reigning Super Bowl champs (6-1) have been undefeated. Also, according to a statistic aired during the game, Kelce averages 99 receiving yards per game when Swift is in attendance. Without Tay-Tay in the stands, it falls to 46.5.

Neither Kelce nor Swift nor their camps have publically commented on the nature of their relationship. Kelce has talked about spending time with her and dealing with the attention she brings to the table.