Taylor Swift Debuts On Brittany Mahomes' Instagram W/ Boozy Photo

Taylor Swift and Brittany Mahomes' friendship is Instagram official ... 'cause the wife of the Chiefs superstar QB finally shared a personal pic from their weekend in NYC where the singer spent some quality time with a few fellow K.C. WAGS!

Of course, Patrick's partner hit the Big Apple with Swift and her VIP gal pals Selena Gomez, Sophie Turner and Gigi Hadid a few days back ... locking arms with Travis Kelce's new boo outside the Bond Street restaurant.

Judging by Brittany's new social media posts, it looks like Taylor made some time for her new friends on Saturday, too -- Chiefs backup quarterback Shane Buechele's wife, Paige, and tight end Blake Bell's partner, Lyndsay.

As we previously reported, Paige and Lyndsay were spotted leaving Taylor's TriBeCa apartment following the Chiefs' matchup with the Miami Dolphins (which was in Germany) ... with the ladies decked out in gameday gear.

The foursome posed for photos as they enjoyed some champagne (we know Brittany loves her bubbly) ... and it's clear they've already hit it off.

We're guessing not everyone's going to love the photo sesh ... this is presumably why Travis' ex, Kayla Nicole, unfollowed her once-bestie, Brittany, explaining it was necessary in order to protect her mental health.

It was seemingly the last hurrah for the group ... at least for the foreseeable future. Swift's international tour kicks off on Thursday in Argentina.