Tony, along with 30 other sailors, agreed to work on a ship owned by Steven. Steven promised to pay each sailor $150 a month for the length of the voyage (from London to the Baltic and back), and the sailors promised to work on the ship and do anything needed in the voyage regardless of emergencies. 16 sailors deserted the ship after the ship docked at Cronstadt, leaving the ship unseaworthy for the journey back. Steven could not find replacements, so he promised the 14 men (Tony + 13 other sailors) that the wages of the 16 deserters would be divided between them if they fulfilled the duties of the 16 missing crewmen and sail the ship safely back to the port. The sailors agreed, work around the clock and sailed the ship safely to the port, but Steven refused to pay the additional wages upon arriving back in London. Tony sued Steven for the breach.

Required:
Is Steven legally bound to keep his promise to divide the wages of the deserting sailor to the remaining crew members or not? Justify your answer by discussing the legal reasons and mention at least one precedent to support your answer.