If that Silver dude is still trying to pass as his older sister, and her claiming to be 16, they can still get terminated for posting underage nsfw content. Photos of minors are a big no-no in the tumblr TOS. Have enough people send a abuse report with links to them claiming their age is under 18 along with the pics and even mention it’s against TOS and they’ll get the blog deleted.
Not to mention it’s a federal crime that’s all on him because he didn’t send it to any specific person, he posted it publicly for everyoneto see. That’s quite some time in the big cells.