Ya but is there a certain pattern or option i must choose to get rid of him or what? I don't want to share Ann with him.
In order to be able to get rid of him, when given the choice, you must basically tell him to go f*** himself (on one of the first meetings)
The other two options will lead to sharing.
The 'Goodbye Eric' story arc will start, once he accuses you of theft.
If you managed to get the two compromising pictures of him by then, Alice will be your key to success. Otherwise Lisa will help you.
For details how to get rid of him, check the ingame hints and/or BlackPanthers walkthrough. Maybe you can optimize your path there, but I doubt it. Too many things are interconnected..
And don't mind the "this game is not for you" nonsense.
On War path Eric is barely present and most story arcs don't include him either way.