How to credit a Duet to a second person:

Client 1 buys the Duet.
Go to the Profile Page of Client 2 who will be sharing the Duet.
Go to Relationships > Assign
>Add New Relationship
>Select Client: type name of Client 1 in the Search box
When you have the correct name for Client 1, in the drop down menu box, select
Client 1 shares series with Client 2
>Save and Close the Profile
Sign in Client 2 and it will show the Duet as an active pay option.