This song is about how our culture is becoming more and more about just sex. Everyone is becoming all sexualized from earlier and earlier ages, and all they care about is scoring for one night, or scoring that one person, with no thought for the future or for responsibility. They're saying that guys go around fathering kids with no intention of supporting them, and girls get pregnant without thinking it through. It's making us seem all seem like oversexed animals (like the dog mentioned by the last interpretation.)
sex seems rather futile and worthless when there's no love involved- it just is made to sound stupid, and cheap, like in this song.