how to convince your mom that you dont smoke weed?

[Princess Psycho]

Well first of all what you need to do is get your sister and then smash her head against a hard object like the table a few times, this will reinforce the concept of respecting your privacy. As for your parents if they actually knew anything they would know that smoking weed affects your judgement and that you would be lethargic and that by giving your sister a savage beating would suggest you are not smoking it. It might be a good idea to tie your sister to a chair and remove her teeth with a claw hammer just to make sure she does not tattle tale on you again, though if you don't want any blood or shattered teeth what you can do is cover her face with a wet flannel and pour water on it, as a rule after seven seconds of this treatment she will be thoroughly persuaded never to do it again though to be extra sure you could use electrodes and a car battery. The other alternative is put some weed (well just use some dried basil as your mom wouldn't know any better) under her pillow and see what happens when you mom finds it on her.