How to take into account authorization on the site through social networks?

Question

Facebook

Authorization on the site is implemented by logging in through user accounts in social networks. The user follows the authorization link to the social network site, where he gives his permission and returns to the site. Analytics considers that the user first leaves the site, then comes as a repeat visit with a referral from the social network. This is not correct for two reasons:
1. This is one session of one user on the site, not two.
2. Authorization addresses in social networks are not referrals, there are no links to the site.
How to correctly configure Analytics to take into account authorization on third-party resources?