I am using the Journal 3 theme.

How can I make it so once I sign into a customer account, if not an affiliate show option to join on my account page; if already an affiliate then auto sign in? And once signed out, sign out of all accounts.

I have a similar rule for my customer and seller account that was done by someone on Fiverr.com and basically it works by the email address. when customers sign in to create a affiliate account the information is pre-filled and cannot be changed. so that way all accounts are link, if user wants to change the email the will have to contact admin where we will change the email on all accounts.