While there, the fellas also played a fun game called "5 Seconds with 5 Seconds of Summer," where Ellen gave fans exactly 5 seconds to say anything they wanted to the guys. Most girls spent their time giggling, laughing, and screaming -- but it was amazing nonetheless.
The guys are ready to hit the road again with shows in California and Arizona in a little over a week. And, on Nov. 23rd, they'll be taking the stage at the 2014 American Music Awards alongside other announced performers, including Taylor Swift, Iggy Azalea, Lorde, and Selena Gomez with her emotional new single.
Watch the video above to see how 5SOS changed their lyrics to charm Ellen!