少男 almost always pairs with 少女 (shàonǚ, 'young girl') — together 少男少女 is a common set phrase for 'teenagers / young people' in titles of books, magazines, and songs. Standalone 少男 is less common in speech; 男孩 (nánhái, 'boy') is more everyday.
memory
少 'young' + 男 'male' = 'young male'. The 少 here is read shào (4th tone, 'young'), NOT shǎo (3rd tone, 'few'). Same shào in 少年 'youth/adolescent' and 青少年 'teenagers'.
