ULPT request: How do I make my roommate regret taking my cigarettes?

How do I make my roommate regret taking my cigarettes again?

Well obviously im not trying to kill him here

Also forgive me for the post format I’m on my phone.

I live in a dorm with my roommate and he keeps stealing from my packet everytime i have one lying around on my drawer or something.

Even though i confronted him about it and he denies everything.

How do i make him stop without poisoning my ciggs lol, maybe a decoy pack with laced mint extract that will make his eyes water everytime he tries to smoke it?

And before someone tells me just hide them in your drawer or under your bed, Due to some space issues in our dorm, not much space to hide stuff besides my drawer which is pretty accessible.