What do you all think of masturbation?

I have nothing against catholicism but it is awkward to me that they find masturbation as a sin. They claim it is adultery but how is it adultery when you are unmarried. I know the bible speaks of fornication, adultery, and sodomy (i do none of those things) but where does masturbation come into play. Masturbation is a child's first ual encounter with themselves and i think Catholic priests would take pride in knowing that their youth are keeping their ual urges to themselves rather than committing the sin of fornication.