Seller employed Broker to sell his property in Astoria Park. Broker subsequently negotiated a contract whereby Seller and Buyer agreed to sell and buy the property in Astoria Park. The contract was prepared and typed in Broker's office. As there were numerous conditions and terms that had been agreed upon by Seller and Buyer, the contract was quite long and involved. Since the amount of deposit obtained by Broker from Buyer was equal to what his commission was going to be, in the middle of one of the long paragraphs was the phrase "In the event the buyer defaults, the deposit shall be retained by the broker as his compensation." At the time Broker presented the contract to Seller and Buyer for their signatures, he made no mention of the phrase he inserted in the contract, nor did he recommend that they read the contract. However, he did not in any way try to influence them not to read it. Seller and Buyer signed the contract without reading it. In the area, a 50/50 split of defaulted deposits is customary between sellers and brokers. Buyer subsequently defaulted. Seller asked Broker for 50% of the deposit. Broker refused and showed Seller the phrase he had inserted in the contract. What should Broker do?