Having fun is acceptable. However what you are justifying in that video cannot in any way be considered "fun" or "medically beneficial". For one, those are all underage kids smoking and drinking alcohol. Not only are they putting their own lives at danger but also the lives of others. These same kids under the influence get into car accidents injuring or killing themselves and others as well.
Secondly, making out and hooking up with random strangers and that too while under the influence puts the person at risk of acquiring various STD's. And the person who already has STD will be spreading it amongst those who don't have it. I have had the misfortune of knowing a few people who have acquired mono through shared drinking and making out with complete strangers at high school and college parties.
That behavior in that video can in no way be considered "fun" and "medically beneficial". Rather, that is purely irresponsible behavior which has become very common amongst American teenagers!
And these are the people who are supposed to inherit the American nation from their predecessors and expand upon (more like leave neglected) the hard labor of the older generations??
George Washington and the founding fathers of America as well as Abraham Lincoln would shoot themselves if they were to see the state of their nation today. These men struggled with their lives hanging in the balance for the sake of this Nation, and to see that it all leads to this is very disappointing and heart breaking indeed.