Possible Clues:

• Private meeting place where parent and child, one an idiot, say, raised
• Of a secret society
• Boy, one in raincoat, is from a lodge, perhaps
• Like a lodge, with mum in charge protecting her boy
• Type of handshake
• Mum and boy in charge of lodge?
• Related to Freemasonry
• Of a secret male fraternity
• Branch of secret male society