Possible Clues:

• Be in a dodgy situation — hesitation and neck may be broken
• Behave rashly with society girl over spare diamonds
• Stick one's neck out
• Act riskily
• Take risks in feeble attempt to keep fish fresh?
• Court danger and faint, tucking into chilled fish?
• Cut a fine figure maybe in a dangerous position
• Take risks - fish displayed thus might not stay fresh for long
• Look for trouble
• Put oneself at risk, ducking the likely outcome?