"To the foxxy-est producer ever!" the handwritten card reads. "Ur just getting better with time! Thank you for making my wildest dreams come true!"

Additionally, an email from Pebe Sebert, Kesha's mother, to Dr. Luke congratulates the producer on the birth of his daughter--"I know you are going to be a great dad"--and another from Kesha in 2009 calling him "part of our family."