Stonestreet v. Southern Oil

Stonestreet (plaintiff) leased a filling-station lot to Southern Oil (defendant), which held an option to purchase; when the lot's water supply proved insufficient, Southern Oil and Stonestreet separately agreed in writing to split the cost of drilling a well, and Southern Oil separately promised, outside any written agreement, to repay Stonestreet's half of that cost if it ever exercised its purchase option. Southern Oil did exercise the option and buy the property, but never reimbursed Stonestreet as promised; Stonestreet sued for that amount and won at trial, and Southern Oil appealed.