JSOM context newly created id reference question when creating more than one item

I am using the COM Javascript/jQuery to get, create & update some list items. I have two lists and everytime I create a new item in one list, the newly created id is something that I want to grab in order to place in a FK like field in the second list (not even using linked at this point, just a generic integer type field).

Simple enough, but what if I want to through this process into a loop and create 10 at the same time.

after I create a new item using

function createItem(tbl, obj, callback) {
    var cxt = new SP.ClientContext.get_current();
    var list = cxt.get_web().get_lists().getByTitle(list);
    var createInfo = new SP.ListItemCreationInformation();
    this.listItem = list.addItem(createInfo);
    for ( var prop in obj ) {
        listItem.set_item(prop, obj[prop]) 
    }
    cxt.load(listItem);
    cxt.executeQueryAsync(callback, Function.createDelegate(this, this.onQueryFailed));

}

_createItem ('ListA', { Title: 'First List Item' }, function () {
      var thisId = listItem.get_id();
      var other = {
           Title: 'Second List Item',
           RelatedId: thisId
      };
      _createItem('ListB', other, function () {
           console.log('created');
      });
});

When I use the above inside a loop to create 5 records in both lists it doesn't work, the thisId/item.get_() typically returns a -1 even though the items are getting created in both lists. I am sure there is a perfectly good reason this occurs, I am just unsure of it and was hoping someone could help me understand, and perhaps if there is a way to get at what I am trying to do properly.....I have tried deep copies and this doesn't seem to matter??