write it with easier words but keep it professional: The limitation on John's ability to remarry is total and lifelong, which is often viewed as an excessive and overly limiting condition. Courts usually deem such extensive limitations as unenforceable because they excessively infringe on personal liberty and the capacity to remarry. John probably has a defense in this case. The complete prohibition on remarriage stipulated by the contract is likely unenforceable as it contradicts public policy