My maternal Grandfather was a functioning alcoholic. Only 4 children out of 7 (Including my mother) that did not have problems with the bottle. Half of my cousins have alcohol issues. I used to have more than 1 or 2 back in the day, but now, a sip of the chalice at Mass on Sundays and that is about it. Maybe 1 drink every 3-6 months, MAYBE. Entire years have gone by with out one. I won't stop someone else, figure it is their choice.
@vergaSame here,but I do confess to trying to convince teens whose parents I know are drunks to not drink. I tell them in plain blunt language with no sugar-coating,either.
Then I leave them alone. You can tell people anything,but you can't make them not do something they are determined to do.
The way I see it,you owe it to them as one human being to another to lay out their probably "life road" to them if they get loaded versus life as a sober person. How they live it is up to them,though.
I also tell them that after our little talk if they ever come to me looking for help,they are bleep out of luck. I can warn you,but it is not my job to be your babysitter.