In the clip, Kimmel, proudly sporting a fanny pack, is seen leaving the bar and heading to his truck, only to find Underwood doing some serious damage to his ride.
"Some crazy girl I never met before is taking a bat to my 4x4," the talk show host sings in disbelief.
"My boyfriend's being a total schmuck," Underwood belts back.
Only problem is, "That's not his truck," clarifies Kimmel, adding: "The next time you should think before you freak."
But clearly Underwood's subsequent apology isn't good enough, as Kimmel conveys his sadness over the damage done to his Hello Kitty toy, an Al Gore bobblehead and a poster of the now-ripped James Van Der Beek.
Yeah, we definitely feel his pain on that last one.