Sometimes people lie outright, and sometimes they just don't tell you the whole story. Teens do that too. Why do teens lie? Because from their point of view, they have to. How else can you do what you want to do? The problem is that teens get so used to giving parents half a story out of habit, that they don't give their parents a chance to even say yes, which in many situations they actually might have. But instead they tell the half a story, and because teens are impulsive and live in the moment, they often get caught, and now parents have to deal with a lying issue.
Here are a few cases in point: A thirteen year old girl lives near her town's small downtown area where kids often meet up for pizza or an ice cream. She had her parents drop her off at a school nearby where she told them she was going to a sports event. Apparently, she met up with a few friends there, and they left to walk into town to meet "the boys." (which by the way was the real plan) When the mom called the parent who was supposed to pick up the girls, he told her his daughter had never gone to the school, but he dropped her off in town and that's where he was picking the girls up at the appointed hour. What a silly lie. When confronted by the mom, the girl said she assumed her mom would have said no to letting her walk around town. And she said, I did go to the game (even though it was for 5 seconds) so I didn't lie, I just didn't tell you I was going into town. Oy vey!!!
Another story. a 15 year old girl who lives 30 minutes by train outside of New York City tells her parents she is going to sleep over so and so's house. Parents drop her off there. Parents are home, all is well. She finds out from a friend who was riding the train back from the city at 10 PM that she saw her daughter on the train. Whaaaatttt! The mother exclaimed, her daughter knows that she is not allowed to go into the city without adult supervision. Apparently the sleepover house parent who drove the girls to the train station and picked the girls up there at 10:30 PM never questioned this girl as to whether her parents had given her permission to go into the city at night on the train, and the girl never said anything about it and went on her merry way with her friend on their adventure.
In both cases, the girls never gave their parents a chance to even discuss their desires, and now they have to deal with the consequences of lying... That's the teen "feeling" brain for you. The impulsive need to go and do is so strong that it belies rational thinking. And that is the point. Your teen needs to know that you won't always be the parent of NO. Sometimes as parents we do get into the knee jerk reaction NO's because your teen demands rather than asks, and that pisses you off, or catches you when you are busy, and just to shoo the issue away you say NO, or they have asked permission for a similar thing and you have said NO, so now they know not to ask but just do.
In both of those cases there was room for a non-no answer. It is true that in the past these parents had said no to similar requests, and the girls felt they had no other choice. Your job is to help you kids come up with a plan that could possible make it a yes. For the NYC girl a compromise might have been reached. " I get you really want to go into the city alone with your friends. I don't feel safe having you go in at night, but you could go late afternoon, and take a train home at 7:30 or 8 and still have time to get dinner and walk around in the early evening. I'm guessing that would have been an OK compromise. In the walking into town case, the girl knew the mom was uncomfortable with the kids rambling around town. Mom and daughter could have come up together will a plan that would have made mom comfortable.
Your job is to say to your kids: "Give us a chance. Maybe we can find a way to make it happen for you that feels good to both of us. Don't give us that chance and you might get caught in your lie, and end up with a consequence that is unpleasant. I know we sometimes say no without thinking, and we will work on that so you don't need to lie."
Go back to my blog on the A+ parent for an example of how well this can work. Remember helping you kids to come up with a plan that works for both of you is so much better and more pleasant than sitting home with a grounded teen. Nobody wants to do that!