This works like a charm:
<a class="btn btn-large btn-info" href="<%= signin_path('twitter', group_id: @group.id, auto_join: 'y') %>">Login with Twitter</a>
However, when using FB it no longer keeps the parameters after logging in. What can I do to make sure my parameters persist through?
<a class="btn btn-large btn-primary" href="<%= signin_path('facebook', group_id: @group.id, auto_join: 'y') %>">Login with Facebook</a>