My sister wants me to lie for her

My sister wants me to lie to my parents about her using drungs she wants me to tell them am the one  smoking weed I am but she was too and a couple of times she use cocaine and if I lie that she's not am going to be call a lier because am the one that told on her what should I do?

You both should tell the truth! People make mistakes, we are All human beings and none of us are perfect. If you lie about this, what will be next? Your parents may be upset but it won't last for long. I wish that I would have said something about my sister. She turned out to be addicted to crack cocaine and now is an addict with four kids. If I would have done something when she was just smoking weed or doing coke, maybe she would have had a chance...