Is there a way to prevent a user from being in more than one member group. I've looked into the MemberService.Saving event and the groups don't seem be be assigned there to be validated and cancelled..

Looking for something like:

private void MemberService_Saving(IMemberService sender, SaveEventArgs<IMember> e)
        {
            foreach(var m in e.SavedEntities)
            {
                  if (m.Groups.Count>1) e.Cancel = true;                  
            }
        }