when a girl is fairly, and sometimes extremely attractive, yet she is much younger than she appears. usually 2 -3 years younger. she is boundary line for 16-17 year old men, and prison time for men over 18. pedo piffs are very similar to jail baits. Pedo Piffs often have myspace pages with risque photos, and a false age and wont tell you their real one until u ask them.
Guy 1: hey i met this grl on myspace the other day, she lives around us.
Guy 2: aw man stay away from her, shes 100% pedo piff.