It's your home and they can choose whether they want to be guests in your home. I don't know your habits - do you normally smoke inside? Do you smoke often? Do you have good ventilation? If the smell of smoke is strong, it may impact their decision more.

The question becomes whether or not it's important to you to have these non-smoking friends visit you at your home or whether you are willing to meet somewhere "neutral" for both of you where you can step out for a smoke break while they are not bombarded by the continuous smell of smoke (if that is the case).

I'm a non-smoker. I have two friends, a couple, who are chain smokers. I love them dearly, and because of that, I will go and visit them for several hours at a stretch in their home, which literally reeks of cigarette smell from the moment I get to their door. I make sure to take allergy medication prior to going and take some with me to re-dose while I am there, as required. I don't complain. I don't say anything. It's their home and I have made a choice, because I enjoy them as people, to visit them in their home. Once I get back to my own home, everything I was wearing goes into the washer immediately and I go into the shower. I smell as though I have been sitting at a smoky bar for days on end. My hair reeks. My skin reeks. My mucous runs brown. This couple has other friends who will only socialize with them by going out somewhere (restaurant, park, third party's home) or having them over (they won't go to their home). I know that hurts their feelings.

Unfortunately, I guess you find out who among your non-smoking friends loves you enough to see you regardless. Some, however, may not be able, medically, to abide a smoky environment. But for those who do choose to continue to visit you, please, please realize it's not because they like or condone your smoking, only that they love you enough to overcome it.

When you quit, if you quit, it has to be for yourself (unless you are better motivated by doing things for others - some folks are).