Jason Kelce's "Monday Night Football" debut shirt -- and his NSFW comment that accompanied it -- had nearly everyone in stitches ... including Travis Kelce and Taylor Swift!!
At least, that's what the Kansas City Chiefs star said on Wednesday's episode of "New Heights" ... revealing that when he and his girlfriend saw the whole scene unfold on ESPN this week -- they giggled hard.
"Me and Taylor were watching that," the tight end said, "absolutely dying laughing at it."
If you missed it, the hilarious scene all went down just prior to the 49ers vs. Jets game in the Bay Area ... after Jason had apparently left his travel bag in his truck.
The elder Kelce bro. hit up a nearby mall for a replacement shirt -- and when it was so obviously too snug for him ... he made a remark live on-air that his "t**s" were struggling.
While there were some haters who found it a bit crass ... Travis said he loved it -- calling it "the perfect thing to open everybody up to what they were going experience for the next 18 weeks."
Jason, meanwhile, didn't seem to have any regrets ... and also was pretty sure no one got in trouble for his off-the-cuff comment.
All jokes aside, Jason -- who signed with ESPN this offseason after retiring from the NFL -- said he enjoyed his first broadcast and looks forward to the upcoming season ... with or without more wardrobe mishaps.