John Mayer really made one fan’s day earlier this month. Us Weekly reports Mayer was shopping at a music store in New York with girlfriend Katy Perry on July 5th when he spotted 16-year-old Julie Fermin checking out an expensive guitar. Fermin, who’s been playing guitar since she was 11, told Mayer she couldn’t afford the axe herself, so he decided to buy it for her as gift. Fermin said she and her friends were excited to meet the couple, and John agreed to pose for a picture with them. When he asked her which guitar she liked, she showed him but said, “I can’t afford it.” Fermin and her friends then left the stars alone, and after the couple left, a store employee told her, “John Mayer just bought you that guitar.” "I was so shocked," Fermin gushed to Us. "I started crying and screaming. I cannot describe all the emotions I felt at that moment. I just knew I was the luckiest and happiest person alive."