Ohhh... the glass thing is scary. I'm glad he's ok.
Both my kids were/is very adept adult manipulators, which I've been told (and I agree) is an anxiety-control measure. In fact, DD9 (6 then) kept her grade 2 teacher so on her toes that she (teacher) told me she's never seen a child that skilled at adult manipulation.
DS8 is better now, but also had almost no regard for safety when it came to his curiosity and impulsivity. O.M.G. From the time he could move away from me as an infant until he was about 7 years old my life was all about CONSTANT SUPERVISION OF THE BOY. lol.
Anyway, for the lying, what ended up working was a lesser punishment for a confession Vs. a greater punishment for being caught in a lie. For example, if they lie, they lose coveted item for two days, but if they tell me they lied, or if they confess to having done something wrong, the loss is only for one day, with a reminder that if they had lied, it would have been two days. I managed to catch them in enough lies to earn myself the disciplinary credibility to make it work ;p
Have you ever told your son the story of the boy who cried wolf? This is another tactic I've used. I've told them this story several times. I'll call them on it too: "So you lied about having to go pee just so that we would go into this donut shop? You're like that boy who cried wolf! If you do this enough, I'm going to stop believing you. What will happen when you REALLY need to pee and we don't look for a bathroom because I think you're lying?" etc etc.
The thing that bugged me the most from my kids was DS(then 5 or 6) pretending to be choking, and then laughing and saying "just kidding!" That would result in time outs, and long discussions about how you DON'T lie about safety and emergencies.
SO glad my two are past this phase... good luck & hang in there
