Question: how to tell the difference between a boy and girl leopard gecko?
Answer: The back of their thighs have femoral pores. Both male and female leopard geckos will have femoral pores, but the male's pores will generally be larger. ... 
The preanal pores are generally more noticeable and are more of a V-shape. ... 
The base of their tail will have two hemipenal bumps/bulges.