Hey schro3f, no by "deleting my relationships" I mean editing *my* personal contact card in my contacts. Siri learns who your brother, mother, spouse etc are and I deleted those fields out of my contact card.. Then I turned off contacts and Siri, and when I turned off contacts that is when my iPhone asked if I wanted to keep the contacts on my phone or delete them. Since I have them all in iCloud I chose to delete them.
For your situation it'll be a bit different, you may have to turn off contacts in your Gmail account under Settings -> Mail, Csontacts, Calendars and then turn Siri off, reboot the phone then turn them back on. The iPhone May not ask you if you want to keep all your contacts on your phone and I'd be careful of this, making a backup of your contacts first off of Googles servers, as I'm not sure how the syncing will work if you have to manually delete all contacts off your before turning off Siri and rebooting.
Does that make sense? Respond if you have questions or need help, I don't want you to loose your contacts trying to fix this!!!! :)