Should i take the blame for my best friend?

Sooo... i used to smoke weed but stopped after my parents found my stuff. My best friend also did but stopped and wasn't caught. He stores a bong in this tunnel in his back yard. Well with a recent storm, water washed it into his backyard and his mom found it. His mom is from Colombia and threatens to send him to live there. He told his mom that the bong was mine and wants me to cover because she already knew I smoked before. I just don't want my parents to think I'm still doing that stuff, but I don't want to let my best friend be sent to Colombia. WHAT SHOULD I DO???