The 35-year-old rocker, who has previously dated stars including Jennifer Aniston, Cameron Diaz and Jessica Simpson, wants to show his girlfriend of five months that how serious he is about her, reported Contactmusic.
"John has put some serious effort into his Christmas gift for Katy. Since they met he has been trying to prove he isn't the guy everyone says he is. This should definitely prove that - every little detail on the guitar shows how much he thinks of her," a source said.
The musician has had the guitar covered in intricate designs, including Perry's initials and the date they first met.
"John and Katy have decided to give it a proper go and want to find a place in LA to share. But lots of people are willing them to fail. They row a bit and have quite a turbulent up-and-down relationship, despite it only being a few months old..."
