My mother absolutely despises getting high. My father seems to think it's bad mostly because it is illegal, and he's not as crazy as my mom. She used to search my room, search me, call my friends' parents and tell them I was a druggy and so was their son, threaten to call the police (for smoking weed!), threaten to make me go to "rehab," keep money away from me, and distrust me. Nowdays it's not so bad, mostly because I don't smoke often and definitely not when I know I have to deal with them. And they think I've quit.
I've been caught smoking weed more times than I can count. My parents have caught me in the act just once or twice, but they've guessed and known that I was blazed numerous times. Most of the time, they would ignore it for a while and then all the sudden one day burst and say "we know you were high last monday, tuesday, wednesday, and friday, and yesterday and today!!!!!!"
This all started back right before the 8th grade. The first time I ever smoked and got high, it was a Tuesday night (a school night!) and I had to be home just 15 or 20 minutes after smoking. I was basically geeking hardcore riding my bike home. I went inside and tried to run upstairs without my mom seeing, but she just had to come out of her room and stop at the top of the stairs and force me to talk to her. I just kind of mubled a bunch of shit and she said "Are you feeling okay?" and I mumbled some more shit and went to my room. For the next 3 or 4 times I got high she was suspicious and forced me to talk to her, so that she could look into my eyes and whatnot.
One of the most notible times of my parents catching me in the act was one day, I decided to have just a tiny few hits in my bathroom. I had made a pipe out of a metal flashlight and a doobtube out of dryer sheets. My parents were downstairs watching a movie. I had the shower running and the tube ready... but one of the hits I guess I just forgot to blow into the tube. Also, apparently my mother had her ear up to the door and could hear the lighter clicking.
I was just about to put my shit away when I hear the door unlock from the outside. I immediately bodyslammed the door shut, locked it, and pulled out the drawer to block it. My mother reopened it but could not get in. She was outside yelling for me to open it.
I took the pipe and lighter and put them under the bag in the trash can....... and.... I took the bag of weed, spread my butt cheeks... and you get the picture.
Anyway, I opened the door and said to my mom "Leave me alone I was masturbating." LOL!
My mother replied, "So you get high and masturbate at the same time, huh?"
Anyway, they ended up finding the pipe/lighter but not the weed

I had a long long long lecture and less trust than before. Grounded for a while as well.
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There is another story, involving DXM, that I would like to share.
Once upon a time I decided I wanted to chug a bottle of Delsym cough syrup in my bathroom, so I did. The crinkle of the safety seal was enough to set my mom off, and as I opened the door after chugging I saw her across the hall in my room "folding laundry." I knew something was up immediately because 1. she does not fold laundry in my room and 2. she does not fold laundry in my room UNLESS she wants to make it impossible for me to avoid her.
She walked up to the door where I was standing and said, "Why did I hear you flicking a lighter in the bathroom?" And before giving me a chance to answer she digs her hand into the pocket with the safety crinkle wrapper. It was obvious it was a medicine bottle seal and so she says, "What else do you have?"
With her blocking my way and not letting me get through I finally just show her the almost-empty bottle of Delsym. She freaks The FUCK out and says, "START THROWING UP, NOW!!!!" So I get on my knees and throw up just a tiny bit of the syrup as my mom ran into her room to find the ipecac. Her frantic actions led my little sister to believe that I had attempted suicide.
Anyway, I told her I threw up as much as I could. She could find the ipecac so she drags me into the car so we can go to the grocery store to find some. We go into Kroger and she couldn't find it... I sarcastcically suggested, "Why don't I just drink some hydrogen peroxide?" SOOOO she buys it. We get back to the car and I refused to drink it.
I told her to call poison control because I assumed they would calm her down and let her know that it wasn't going to kill me or cause any permanent damage... However the lady on the phone made it worse. "You need to take him to the emergency room right away, his life is in danger."
So anyway, by the time we get to the hospital I was tripping my balls off, barely could walk. I remember the receptionist laughing at me when my mom said, "Yes, we called about my son chugging cough syrup."
Anyway... this is getting really long so Ima try to shorten it up. Basically the doctors asked me if I was trying to kill myself and I simply said, "No. I was only trying to get high." The doctors told me I would be okay and they told my mom I would be okay, but they were going to keep us for a few hours "until it wears off." HA! They thought the effects only lasted up to 4 hours!!!!!!!
So I spent the next 3 hours or so in the emergency room, my mom crying, calling my family and stuff, and all that. My little sister still didn't know I wasn't trying to kill myself. I watched South Park for most of the time. It was funny.
Finally they released me, thinking I was mostly sober. HA! I was completely fucked up! The doctors had told my mother that the effects were similar to PCP... of course my mother thinks PCP is the KILL KILL RAPE RAPE GO INSANE drug, so of course she assumed that I would murder her if she did anything to upset me. I turned on the radio onto Infected Mushroom. It was pretty loud, and very trippy. My mother said NOTHING the ride home, probably in fear of me snapping and slamming her head into the window. Little did she know I was completely euphoric and would never hurt anything.
So those are my two best stories. There are more... I might post em another time.