The Kansas City Chiefs tight end opened up about his relationship during an interview on "CBS Mornings" in anticipation of his Pepsi commercial with Megan Thee Stallion ... based on the iconic 2004 ad starring Beyoncé, Britney Spears, Pink and Enrique Iglesias.

TK's cracking up in the clip, still dressed in his Roman gladiator garb for the commercial ... saying it seems he's chosen the arm candy role -- which he says is basically a tradeoff for all the cool, fun activities and sponsorships he takes part in.

As for how his family's handling the fame ... Kelce says they're slowly getting more comfortable with it -- except for his big bro Jason of course, who was a seasoned media pro long before Trav went public with Taylor.

The one-year anniversary of Travis and Taylor's first public hangout is fast approaching ... remember, we obtained video of the two speeding off into the night after the Chiefs beat the Bears last season -- hinting at a blossoming romance between the pair.

The two have been spotted together at football games, concerts, romantic candlelit dinners and a whole lot more since then. It seems they're still going strong these days -- with Kelce's reps slamming an alleged "breakup plan" that made the rounds online earlier this week.

The duo recently hosted an end-of-summer bash for their celeb friends at Taylor's Rhode Island home too ... with the guest list boasting Blake Lively, Ryan Reynolds, Channing Tatum, Bradley Cooper, Gigi Hadid and other big names.