Boundaries are soooo important.. I think .. you can avoid all the fuss and drama by using strategies... and tricks.. and psych them out..before they use their cheap psycho on you :)
Here is my 2 cents worth .. only because i'm a mum of teens.. and through trial and error.. not bcos im some expert.. or anything .. and i could be wrong too.. ! But it worked for me..
try motivating them to do chores through positive reinforcement in exchange for privileges. Perhaps you can draw up a list of chores and some kind of schedule or deadline and let them choose which ones they want to do. If they dont there will be consequences (eg: if they dont help the laundry get to the ironing load, they wont get clean clothes and this will have an impact. I exchange chores for things like internet and x-box time.. Be gentle.. not harsh.. to earn their respect so that they can give it easily.
I agree that this kind of discipline has to start from a young age - i had them helping out as soon as they could but i made it a game.. We sang, pranced about or pretended to be witches on broomsticks - whatever it took... had to get chores done but i had to tend to the kids also, so i involved them - took longer but it was done. Now they are responsible enough to know that housework is teamwork - boys and girls, and whoever has the time for that particular chore, does it. Nothing is perfectly tidy at all times, but that's ok .. there are other things to do. However, they won't be going off with their friends if their rooms are not clean, and they wouldn't even ask.. because.. the main thing is .. I do not allow them to turn my NO into a YES OK. (as far as I can . I mean.. sometimes rules have to be broken depending on the situation.. but otherwise, they stick.)
Plenty of hugs and kisses and 'i love you' and thank you goes a lonnnnnnng way. But not just thanks. Say WOWW !!! that was awesome! you were SUCH a big help !!! (not toooooo overly drammatic.. but enough to hit home) repeat this .. sometimes.. ;) (cheap psycho here). And let them overhear you say on the phone to someone - weave it into the conversation.. 'he/she did the dishes and it was such a big help! (or smilar praise). Don't let them know that you know they are listening. If they know they are being talked about in a positive light, it will make them feel proud of themselves. they will also know that YOU are proud of them.
Chances are.. they will try harder to impress you .. and make your work load lighter. I knwo many working mums who snap all the time.. yell.. demand.. and simply lose it. It pushes them away from you and the idea is to draw them closer, as close as possible - emotionally. Get into their heads. Watch closely.. listen to what they have to say .. and respect develops both ways. They like apologies too .. after all .. they'r little people, with real feelings, and they will forgive you, and love you unconditionally .. annnnnnddd I am getting carried away here OFF THE TOPIC !!!
Sometimes.. we make things into a problem when its not - i made that mistake sometimes with my kids... but the more time you spend with them... talking to them.. one-one-one.. the more you get to know them.. the easier they are to deal with - in most cases .. not all ! They'r kids after all..