Tell your friends to start acting like friends and help you quit. My buds all chew tobacco, but they were good enough friends that they atleast wouldn't let me have any of their stash. I told them if it comes to blows to just fucking hit me, but don't let me have a chew. I quit cold turkey 4 years ago, my friends were the biggest help by simply supporting me even though they had no desire to quit at the time.
It's alot to ask someone not to smoke around you because we all know how edgy tobacco users can get, but a friend is willing to do such things if they actually care about you and your wanting to quit.