Expand User.Identity properties

I have a site with frontend and admin panel. Both have login page and user should be able to login on both frontent and admin panel with different user. By default User.Identity.IsAuthenticated is used to check if user is currently logged in, I want something like User.Identity.IsAdminPanelAuthenticated. So if a user only logged in on admin panel but not on frontend then IsAuthenticated will return false but IsAdminPanelAuthenticated will return true.