how to end a work item exlicitly without executing it?

i want to find out how to end a workitem explicitly without executing it from the business workplace. we have created a dummy workitem and would like to end it when it is not needed.

i have set up the terminating event in the workitem task but even though the event is raised the workitem is not ended and the workitem is still in the inbox. i was expecting that when the event is raised the event will end the workitem and it will move into the outbox.

am i doing something worng? why isnt the workitem getting ended and move to outbox when the terminating event is raised?