I'm upset about my son's ear piercing, he got it yesterday
What do you think about your son's ear piercing?
I don't understand this planet anymore.
It's expected that you are going to be the responsible voice of your son. It's hard to understand trend but it doesn't mean you need to follow it.
It's not a trend, it's a rebellion against me.
I don't think your son intends to harm you, he just wants to express himself how he wants. How about asking him why he got a piercing, and to tell him your discomfort with it? He may come to see that your feelings are important too!