Masturbation
The Sambia tribe of New Guinea has rites of passage surrounding manhood. They include frequent ejaculation by fellatio. Semen is valued. Masturbation is seen as a waste of semen. Because of this, it is frowned upon but frequent ejaculation is encouraged. The capacity and need to ejaculate is nurtured for years. This is done from an early age through fellatio. This allows the semen to be consumed rather than wasted. Semen is ingested for strength. It is considered in the same line as mothers' milk.