Travis Kelce & Taylor Swift Attend College Football Game After Getting Engaged

6:44 PM PT -- Taylor Swift is also at Arrowhead Stadium for the game ... making an entrance with Brittany Mahomes by her side. Fans are heard yelling out "congratulations" to Tay.

Taylor and Travis were also seen on the broadcast sitting next to each other in the suite.

Travis Kelce's traded the garden where he got engaged for the gridiron ... 'cause he was seen out just days after he and Taylor Swift made their announcement.

The NFLer hung out with his big bro, Jason Kelce, chatting it up on the sidelines of the University of Cincinnati and the University of Nebraska.

Check out the pic ... Travis and Jason are both repping UoC -- they both went to Cincinnati before beginning the pro careers that will land them both in the hall of fame one day.

Travis hasn't been seen out much recently ... and, this is the first glimpse we're catching of TK since we found out he got down on one knee and asked T-Swift to marry him.

As you know ... Travis popped the question garden in Lee's Summit -- surprising Swift on their way to dinner.

They posted a few images to social media to announce the news with the caption, "Your English teacher and your gym teacher are getting married 🧨" -- and, it looks like Travis is really playing into the whole gym teacher thing with his spot on the sideline tonight.

Travis was back to business just a day later ... hitting the practice field as he prepares for the Chiefs opener against the Los Angeles Chargers on September 5.

The duo have received tons of congrats and praise from stars as varied as President Donald Trump, Selena Gomez and more since the news broke as well.