He has severe lung damage and keeps ending up in the hospital. The doctors say he can't smoke anymore or he'll die. He has these electrical cigarettes that cause less damage but he can't light them very well.
He can't move well so he rarely buys cigarettes since he needs someone to go with him, and before my mother did and helped him hide them but she has since stopped.
Today I went out with him to a cafe and while I was distracted he bought them, but I saw them later and took them away.
He started begging for them nonstop, saying he wouldn't even smoke them. Saying he'd hate me for life. I offered to give him the cigarette money, so he wouldn't be missing any money but he refused. He just wants the cigarettes and he'll be getting rid of them instead - a clear lie. He is an addict and I've dealt with this before.

Now here's why I might be an asshole - his life is depressing and even without the cigarettes he might die soon. He is severely depressed and smoking is one of the few things he cares about - so should the way I think he should live matter more?

Also, not related to me being an asshole but important to wether I should give them, he lives with me and is vindictive and I have many small pets, I am scared he might take it out on them.