5:26 PM PT -- Taylor Swift was just officially introduced to start the broadcast, and it looks like her box is completely packed -- as she hugs and kisses friends, and hob-nobs with celebs.

No sign of Donna Kelce just yet, but she's almost certainly in the mix as well.

And yes, NBC is fully leaning in to Taylor-mania -- they just did this whole Carson Daly intro recapping the viral frenzy ... and they made a lot of Swift-y song references along the way. Last but not least ... Aaron Rodgers is also in the house -- this just a few weeks after tearing his Achilles and undergoing surgery. The dude is here to root on his underdog team.

It's game time!

Taylor Swift and Travis Kelce's romance is going strong -- so much so that she popped into another football stadium to cheer him on ... this time with some famous pals in tow.

The pop star is again the guest of honor Sunday during NBC's 'SNF' broadcast of the Chiefs vs. Jets game -- in which her rumored tight end BF is obviously playing. Taylor showed up and slipped in through a back area, but got caught on camera entering the building.

This time around, TayTay had some A-list company ... including Blake Lively, Ryan Reynolds and Hugh Jackman, among others. She's expected to be in a luxury suite near the field, and word is ... she'll be joined by Travis's mom, Donna Kelce -- like last week.

As for TS's entourage -- Blake makes sense ... they're best buds, and they were just out and about yesterday together in the Big Apple -- not to mention a starry dinner alongside some other famous ladies, like Sophie Turner and even Patrick Mahomes' wife, Brittany.

Hugh's not all that random either -- he's good friends with Blake's hubby, and they're in this new obscure movie that's coming out next year -- something called 'Deadpool 3,' apparently.

Anyway ... Taylor's appearance is no surprise -- we'd been hearing all week that she'd be here, and they were telegraphing as much by being within a stone's throw of each other earlier this weekend.

We'll see how much of Taylor gets shown throughout the broadcast. FOX kept it mostly focused on the game last week -- but seeing how much of a rating bonanza her mere presence turned out to be ... ya gotta figure NBC will cut to her at least a few times today.

If today/tonight turns out to be as eventful as last week's Kansas City outing ... we're in for a whole lot of news. Travis and Taylor were all anyone talked about -- and now that they're showing PDA in public, it's safe to assume we might see even more of it in the near future.

Some might've thought this was all BS at first, but it's sure looking more real by the day. There were reports that Travis even swung by Taylor's NYC apartment before the game -- so yeah, he's been in her quarters now ... and all signs point to this being an intimate thing.

With Swifties and NFL'ers all flocking for the show ... it's a classic case of worlds colliding.

Trayvis is officially on ... and kickoff is just minutes away!!!