Travis Kelce's stellar performance on the field has him in his "Red" era ... 'cause he made a reference to one of his GF's famous songs after the Chiefs playoff win.

The tight end chatted with reporters after the Chiefs beat the Houston Texans Saturday ... eeking out a 23-14 victory while Taylor Swift cheered from her usual suite at Arrowhead Stadium.

When asked if he feels like a 25-year-old youngin' again, Travis responds he actually feels like he's "22" ... seemingly a reference to Swift's hit 2012 song of the same name.

Travis' eyes light up just a bit when he makes the crack -- so, it seems he knew exactly what he was saying ... shouting out his GF who showed a lot of love for the K.C. fans Saturday.

On her way to her seat, Taylor said hello to a few diehard Swifties ... flashing a toothy grin and giving them a little wave.

And, it looks like she's got a new famous pal, too ... yucking it up with WNBA phenom Caitlin Clark -- who recently did an interview on Travis and Jason Kelce's "New Heights" podcast and is clearly tight with the bros now.

Travis recently admitted that he couldn't be happier in his relationship ... and, it looks like he can't help but give Tay a little nod.

Happy, free, confused and lonely at the same time ... it seems Taylor and Travis' love is the fountain of youth!