"Where a tender is made for the purpose of basing a demand for affirmative relief on it, the rule stated in the preceding paragraph does not apply, but a different rule founded on the principle that he who seeks equity must do equity is called into action, and requires the tender to be kept good. Tuthill v. Morris, 81 N.Y. 94; Werner v. Tech, 127 N.Y. 217, 27 N.E. 845, 24 A. S. R. 443; Knudson v. Fenimore, 69 Okla. 3, 169 P. 478." The Supreme Court of this state has affirmed the above rule in the case of Whitehead v. Stevens, 54 Okla. 337, 152 P. 445, and we quote from the syllabus of that case as follows: "He who seeks equity must do equity.