When adding a "New Affiliation" from and for an existing Request record:

1. It should not default to a new affiliation for the existing Primary Contact.  That is not a logical assumption to make.
2. It should present a New Affiliation form with no associated Contact record. 
3. It should allow for either the easy search and selection of an existing Contact not currently associated with the Request, or the creation of a new Contact, either of which is then immediately added as an affiliation on the Request

This same logic should be applied when adding Affiliations to Organizations.