How do I bypass this Allstar Security sensor?

OK, there is this sensor on the stairs (from Allstar Security (did i spell that right?)) and my mom and dad leave it on a lot and i hate it when it goes off because it is SOOO loud! I always says this ANNOYING phrase (Stairs Motion Detector OPEN) that is SOOO freaking loud!!!!! I know how to bypass it on the control panel thingy, but i was wondering how to like, sneak past ti because there are NOOO other ways of getting past it! PLEASE HELP!!!