Edward Kresser and Della Pyper each had two sons of their own before Kresser and Pyper married each other. The couple owned their home jointly with rights of survivorship. When Edward died, Della executed a will devising the property to the four sons. Seven years later, Della executed a deed naming herself and her two sons, the Petersons (defendants), as joint tenants. She recorded the deed and deposited it in a bank safety deposit box. Della and her two sons leased the deposit box as joint tenants. Edwards sons, the Kressers (plaintiffs), sued to claim a one-half interest in the property under the will. The suit was dismissed because the later deed took the property out of Della’s estate. The Kressers appealed.