Actually, it HAS been done. I did it when the private xp glitch was released. I have no clue how though. I just did the glitch and me and my friend were playing a 1v1 S& and YES, we did get xp. I have no clue how I did it though.
1.Have a friend hosting a party
2.Go to playercard -> edit playercard and press O.
you will see a screen pop up. Highlight "Save and exit"
3. Have your friend switch to private match and edit the game options to: Nuketown/Demolition/Time unlimited.
4.Have your friend switch to Theater and tell him to leave.
5.Wait until an error pops up, click ok. you will see your "Save and exit" screen again click on it.
6.Invite ur friend gack to the lobby and it should start.
If its not starting leave and have your friend invite you back.
1.Have a friend hosting a party
2.Go to playercard -> edit playercard and press O.
you will see a screen pop up. Highlight "Save and exit"
3. Have your friend switch to private match and edit the game options to: Nuketown/Demolition/Time unlimited.
4.Have your friend switch to Theater and tell him to leave.
5.Wait until an error pops up, click ok. you will see your "Save and exit" screen again click on it.
6.Invite ur friend gack to the lobby and it should start.
If its not starting leave and have your friend invite you back.