Julie Metzger and Robert Lehman have been teaching classes on puberty and sexuality for more than 25 years through their company, Great Conversations. Metzger is a registered nurse, and Lehman is a medical doctor. The Pair also just released an updated version of their book called Will Puberty Last My Whole Life? Real Answers To Real Questions From Preteens About Body Changes, Sex, And Other Growing-Up Stuff .