Is it true that size doesn’t matter? Should one testicle hang lower than the other? Get to grips with these and other questions you were afraid to ask about the male anatomy here. This Sex Education lesson looks at the changes that take place in the male body during puberty and explores the male genitalia in detail. Find out the effects testosterone has on the body, what happens if you mess around with your foreskin and get an intimate account of exactly what happens during an erection. Plus 'Does size matter?' answered.