I dabbled in cocaine, I personally don't like it because the high is too short but if you are doing coke once a week after drinking, your chances of buying more grams of coke is just going to increase over time due to tolerance and being comfortable with doing it. You not going to get addicted but it can easily become an habit. Self control is the most important part of the game, since you are drinking and doing lines, you may be playing with a slippery slope depending on your level of self control. .