There are lots of recovering addicts who believe that they can resist the desire to use drugs even when they are around people who still use drugs. Fact though is watching your friends using drugs could evoke memories which would rather stay buried. Memories of "fun" you had when you used drugs and these can make you want to "taste" the drugs just to remind yourself of how it used to be. Don't test yourself if you can. Avoid people who use drugs and you'll be relatively safe.