Prompting private key each time when document gets signed

I have MS certificate authority configured to use digital certificates with a private key. So whenever a person signs a pdf document, it prompts for the private key of the certificate  when the user is signing the document in the first place. But for subsequent signatures in another documents which are opened in subsequent tabs, signature is getting applied without private key since the it is asked in the first place. To prompt the private key again users should close the Adobe reader and reopen it. Is there anyway, it prompts for the password every time when somebody signs the document even though it asked the password in the first place without closing the reader(any registry settings). This is because of regulatory requirement.