Section 61 - Undue influence definedUndue influence consists:
1. In the use, by one in whom a confidence is reposed by another, or who holds a real or apparent authority over him, of such confidence or authority for the purpose of obtaining an unfair advantage over him.2. In taking an unfair advantage of another's weakness of mind; or,3. In taking a grossly oppressive and unfair advantage of another's necessities or distress.Okla. Stat. tit. 15, § 61