pedaphile
Any individual who is interested in establishing a mutual sexual relationship with a person who is of a physically younger age. 
The World Health Organization defines adolescence as the period of life between 10 and 20 years of age. With this said any one who sexually interacts with some one else in this age range is in the "instinctual norm", if you well. Therefore the deviation into pedaphile begins when the 10’s & 20’s and the 30’s & 40’s engage in sexual activities. As you can see it is virtually impossible for anyone with a logical frame of mind to be apposed to the act of this definition! 