Ohio Rev. Code § 3105.50: Waiver of privileges.

(A) A privilege under section 3105.49 of the Revised Code may be waived in a record or orally during a proceeding if it is expressly waived by all parties and, in the case of the privilege of a nonparty participant, it is also expressly waived by the nonparty participant.

(B) A person that discloses or makes a representation about a collaborative family law communication that prejudices another person in a proceeding may not assert a privilege under section 3105.49 of the Revised Code relating to that communication.