17 Year Old Is Constantly Grounded, Disobeying Us

As far as my husband and I know, my 17 y/o son has been smoking weed for about a year or two now. We have, at this point, over the last 1.5-2 years, caught him and grounded him probably about 5-7 times. He is a great kid, and he's very smart. He does decently in school without really trying much at all. We are just very worried that the lying and pot smoking is a sign of something that is really wrong with him. We have showed him many articles about the effects of marijuana on the teen brain, and he doesn't seem to care, just brushes it off. He says he accepts the consequences of his actions, and if there is a lesson to be learned then he will learn it independently, without repercussions from us.What my son says/believes is that since he's 17, and will be in college in about a year, it's time that we stop hanging over him and what he's doing in his free time. As far as we are concerned, until the second he leaves our home it is our responsibility to make sure he is not doing things that will harm him in the future. We catch him stoned quite often, but I suspect he does very little to try and hide it at this point. About 2 months ago, we caught him letting his friends into our house to "hang out" while our whole family, including him, was away. We were absolutely furious with him, grounded him for a month, no phone, no going out, nothing. I'm not worried he would do something this stupid again. I don't think he would, he is a smart kid and is capable of weighing the pros and cons of such an idiotic decision. It's just the pot use and the lying I'm really worried about.. Things seemed to be getting better, until about 5 days ago, we caught him with pot in our house, which we had strictly said was NOT ALLOWED. We grounded him for another 2 weeks. Yesterday I came home from work to his friends walking down our block, so when I asked his younger brother, I discovered that his friends had been over at our house. He swears they weren't smoking, and he appeared sober (he works until 2:30 and I got home at around 5:30). I took his phone and we spent an hour going back and forth about what the best thing to do is. I doubt we'll ever see eye to eye. The lying is the biggest issue here. Why does my son refuse to listen to any of the rules we set?The relationship we have with him is pretty miserable. It's not like we hate each other, but I acknowledge that he does not feel comfortable at all being honest with us about what's going on in his life. I feel like I know nothing about him besides the fact that he likes to smoke weed. It really worries us. Whenever we ground him, he says something along the lines of "dont you get it?? youve grounded me over and over again and i keep getting in trouble for the same things, all it does is make everyone miserable". He says if we really want the lying to stop and our relationship to improve then he has to feel comfortable being around us and he has to respect us. He says it's impossible for him to respect us, look up to us, be honest with us, follow our rules, if he feels like we are constantly at war with each other, trying to stay one step ahead of one another to catch him/avoid being caught by us. When I ask him what a solution that he believes would work is, he says we need to get a fresh start with ground rules that he must follow, but we, in return, have to respect his privacy, stop searching his room, taking his phone, unless he has given us good reason. When I ask what he expects us to do when/if he were to break a rule AGAIN, he says that before calling him down and grounding him, a conversation about why we believe what we believe would be far more effective. He claims every time we ground him it just creates more anger and spite in our relationship and makes things worse.We don't know what to do. We have grounded him over and over again, and we hate doing it, and we know he hates it even more. He says that a shitty relationship with his parents is going to be more harmful to him in the future than any amount of pot he smokes. I just don't agree. I would do anything I could to stop him from hindering his potential, but I've tried everything and it just WON'T WORK. He seems to do what he wants regardless of us trying to stop him. We need some suggestions. If you have questions, feel free to ask and I'll respond as best I can. via /r/Parenting https://ift.tt/2Aw2Rw1