Brad Paisley and his wife, Kimberly Williams-Paisley, have two sons: 4-year-old Huck and 22-month-old Jasper. Huck turned 4 this past Tuesday, and his parents found out just days ago that he already has his first celebrity crush -- on country star Carrie Underwood.

"He likes her and likes her music a lot," Paisley tells PEOPLE. "In fact, one of the things he said that was really funny the other day before he met her was, ‘I don’t like girls,’ and I said, ‘What about Carrie?' And he was like, ‘Oh I like her music.'"

They actually met for the first time last week, when Underwood came to the Paisleys' Nashville area farm. Paisley says, “He [Huck] went out and got her roses -- we took him to Whole Foods and he picked them out himself." The country star says that his son composed a valentine for Underwood that his mom dictated for him and it read, "I hope you have an incredible day and night. Love, Huck."

Paisley says his son is slightly infatuated with Underwood. All of them were hanging out in the studio the day she came over when the youngster pushed the pillows off of the couch and held both arms up over his head saying, "'Carrie, watch! Look how strong I am!'"

Paisley adds, "It was like, 'Wow, the instinct is there already!'"