Hi CAmom. I'm new here, but it sure sounds like your difficult child and mine were separated at birth. Like yours, my son is a master at spinning yarns to get what he wants. He brags about spending "hours" working up a lie to get around our cufew limits and go to parties. Like you, we bought into his verbal traps for so long that he now gets mad when we wise up to what he's doing and don't play along.
And like you, I think, I feel somewhat guilty for not catching on sooner to what he was doing; that if I'd figured it out earlier that he wouldn't have the expectation now that he should get whatever he wants, as long as he can mount a good verbal defense for his behaviour! And that is what's happening. It doesn't matter that we're the Parents; if we don't have a good enough "excuse" for what we enforce, then he disregards it.
I don't have any words of wisdom to help, only words of support and understanding. The hardest thing I'm having to learn is that my 17yo difficult child is now choosing his own path, and unless I'm willing to completely separate him from my family, then I'm merely a specatator and cheerleader.
I don't remember where I read this, and may not have it exactly right, but lately I keep coming back to it:
When children are small, parents are caregivers; there to meet their needs, protect them from harm, and help them safely learn to explore the world.
When children are older, parents become coaches; there to teach, give direction, and formulate plans on how to "play the game". But some leeway is now given to the child on decisions.
When children become tweens/young teens, parents become maps. Children don't want someone telling them what to do, but they do want someone to help them find their way to what they want.
Finally, when children become older teens/adults, parents become guideposts. Unlike a map, Guideposts are only used when you're lost and trying to find your way. At this point in life, the child is now making their own decisions and using their own maps. They only look to their parents - their guideposts - when things aren't working out, and they need help.
For me, it was hard because with my difficult child we never made it to the "map" phase, and instead went from being a coach to being a guidepost almost overnight. Still working though it, but some other wonderful folks have made some suggestions that I intend to follow up on.
Thoughts and prayers for you, and for us all.
Mikey