Hi
I’m always asking stupid questions, so I thought I’d give something back,
When you add a sprite to the screen it will Tween to position. Think it works because of event Bubbling. 
package {
import flash.display.Sprite;
import flash.events.Event;
import fl.motion.Tweenables;
import fl.transitions.Tween;
import fl.transitions.easing.*;
import fl.transitions.TweenEvent;
public class bubble extends Sprite{
public function bubble(){
var b1:Sprite = new Sprite();
b1.graphics.beginFill(0xff0000);
b1.graphics.drawRoundRect(10,10,100,60,10,10);
b1.graphics.endFill();
b1.name = "b1";
addChild(b1);
addEventListener(Event.ADDED, addChildEvent);
}
private function addChildEvent(event:Event):void {
var t:Tween = new Tween(event.target,Tweenables.X, Elastic.easeOut, event.target.x-100, 0, 3, true);
}
}
}