This link deals a lot with moral relativism, which I think is very common in our society, let alone the music industry. Although the link focuses more on the actions of artists, I think his points are relatable to actual song material, as well. If everybody is singing about getting drunk and hooking up with people, then it’s okay, right? Wrong. The norms of society do not determine morality.
If we are aware that the immoral themes of songs are, in fact, immoral, does that mean we cannot listen to them? There is no definite answer. The actions in the song are wrong, not hearing about the actions. But there is definitely still something wrong with the song. Listening to profanity, first of all, desensitizes us the immoral actions, making it more likely for us to do them. It also supports the artist, which promotes him to write more immoral music. It is also abuse of such a beautiful thing. We have talked a lot about how music is a great and powerful gift from God, and to taint it so harshly is anything but good.
That being said, I have admittedly listened to “bad” songs and sang along with them, too. It’s tricky business. I would just say be careful what you listen to. If it makes you uncomfortable, especially, turn it off.