Suppose your parents are both alcoholics . therefore, you cannot trust them

True. But sometimes its the ones who are not drunk that you cannot trust, think before every action you do, Make sure scene is safe and you and your loved ones are safe, Be weary of any outcome when he or she is drunk, and make sure nothing dangerous is laying around to be used against you in anyway or against them self. Be sure to have clean water around as well and make sure your parents are not disturbed as much. You don't have to be un-trust worthy, but you must be weary, Not all drunks are bad, some are actually happy

So you and your partner don’t get sexually transmitted diseases and so your partner doesn’t get pregnant