The ways in which each of you experiences life are pretty different, and you probably didn't even realize it until you'd been together for quite a while -- at which point it may have become, in some sense, too late. You have very different ideas about responsibility and personal ethics, and the differences between you are likely to get bigger and more important over time. You tend to define yourself through hard work, strong ethics and a sense of responsibility and determination in your life when it comes to your career, your relationships with your family and friends, and so on.
These qualities have been established over your lifetime, and they define who you are as a person. But your lover seems to disregard those qualities completely. Traditional values or a conservative work ethic? No way! Not for them. The differences between you feel like an affront to who each of you is as a person -- you, as the more traditional partner, feel offended, as if the best things about you are being snubbed; and they feel rebellious, as if they're being manipulated into living by a code of ethics that just isn't theirs. Obviously, tolerance is needed on both sides -- which might not be possible, if your values are just too different. But if you are to resolve the tension between you, you just have to respect each other instead of getting mad about the ways in which you don't match up.