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Gissing v. Gissing is a case in English property law dealing with Constructive Trusts arising in relationships between unmarried cohabitees.

In the judgment Lord Diplock states:

A resulting, implied or Constructive Trust - and it is unnecessary for present purposes to distinguish between these three classes of trust - is created by a transaction between the trustee and the cestui que trust in connection with the acquisition by the trustee of a legal estate in land, whenever the trustee has so conducted himself that it would be inequitable to allow him to deny to the cestui que trust a beneficial interest in the land acquired. and he will be held so to have conducted himself if by his words or conduct he has induced the cestui que trust to act to his own detriment in the reasonable belief that by so acting he was acquiring a beneficial interest in the land.

See also acquisition of beneficial interests in land.