Think twice before taking on the vintage band T-shirt trend — at least, if you’re anywhere in the vicinity of Twisted Sister’s Dee Snider.

The rocker took to Twitter earlier this week to vent about nonmetal fans wearing vintage metal band T-shirts.

For Snider, it’s “sickening” and disrespectful to wear band merch unless you’re a true fan of the group.

Evidently, Snider doesn’t appreciate how awesome vintage band tees look on fashion heavy hitters, including the likes of Kendall Jenner, Alessandra Ambrosio and Hailey Baldwin.

Maybe he should stick to music instead of playing fashion police.