What is the impact of defining a many-to-many association without setting the inverse=true option?

Person and Group are two entity types with bidirectional many-to-many association.
I have a scenario where the changes has to be persisted from both Person and Group end.

To my knowledge, unless inverse=true option is set on any one side, hibernate is going to treat them as different instances in memory.
Is there any option to set inverse=true and also persist changes from both ends? or is it safe to ignore inverse option?

Thanks