a). a facebook setting that allows you to give in to your sluttastic urges while keeping a "saftey net" around in the event that you're unable to hook up with anything hotter.
b). a great way to set yourself up for some hellish drama, instead of being honest with your significant other.
"oh there's no need to worry about milliscent, we're in an open relationship. yeah we just need some time- SHIT, milliscent's here! act cool, we were just talking...about...chinese fireworks. that's right, chinese fireworks and not hooking up with eacho- hey babe, how's it goin'? you okay, you look upset. you wanna talk about it, i- hey milly, babe come back!"