With my generation, it's hard to "get out", because they all act like this to some degree. I have yet to meet a single person my age that doesn't openly revel in porn, or going to strip clubs, or "smoking that weed, dude!", ect. Even many of the older guys do it too.
It's nothing new, been the same since the 1960's. The sɛҳuąƖ promiscuity was worse than today in the late sixties and 70's, nobody young needed to go to a strip clubs.
Nadir's advice is perfect. The only thing I will add, is that when they talk about drugs and porno, you can make a joke of it, like dismissing it as idiotic. They will not understand the religious aspects, so speak to them from uncommon wisdom of the world, while making a laughing matter out of the whole affair:
Weed - "I do not have the time to confuse my mind and get knocked out by weed, I don't even waste my time watching television or playing video games or texting all day. I have studying to do and things to learn to make a good living. This is the time to get ahead, while I am young, all the older weed heads I see are all poor bums."
Porn - "I do not understand why a young healthy man would want to watch porn, what's it good for? It just gets you frustrated. I'll use my time to improve myself and learn about what life is all about and how women behave, so I can have a good wife for life, rather than an illusion in strip clubs and video."
sɛҳuąƖ promiscuity - "Any girl that is easy, is easy with everybody, so don't think that you are something special. Promiscuity means herpes for life or worse. No, I seek the girls that no one can approach."