In what circumstances will a party be bound by a third party's expectation of receiving something in return?

[31] In Sorochan v. Sorochan, supra, Dickson C. J. C. stated on behalf of a unanimous court at p. 235: In Pettkus, the court held that this third requirement would be met in situations where one party prejudices himself or herself with the reasonable expectation of receiving something in return and the other person freely accepts the benefits conferred by the first person in circumstances where he or she knows or ought to have known of that reasonable expectation…

[32] In Peter v. Beblow, supra, Cory J. said at p. 358: When a claimant is under no obligation, contractual, statutory, or otherwise, to provide the work and services to the recipient, there will be an absence of juristic reasons for the enrichment…