It's best if you imagine Twitch's latest rules update being read by a downtrodden, barely present spokesperson. 

“Content on Twitch is always evolving,” they mutter, unable to recall how many versions of that statement they've composed before. “And we want to make sure our rules work as intended and keep up with emerging behaviors.” 

The behavior that emerged this time is streaming games on butts. That is, using one's posterior like a green screen, overlaying a gameplay feed on it. (Or just pointing a camera at your butt.)

If streaming Fortnite on your butt or watching other people stream Fortnite on their butts is something you enjoy, you'd better get your butt streaming in soon, because this is one emergent behavior Twitch isn't going to let continue. On Friday, “content that focuses on intimate body parts for a prolonged period of time will not be allowed,” the site announced.

Twitch has updated its sexual content guidelines with the new rule.

As Harvey outlined in his report from last week, writing and enforcing fair and equitable rules related to sexual content, including defining what isn't and isn't “sexual,” has been one of Twitch's biggest struggles, in part because creative streamers will try anything it doesn't explicitly ban. 

One of the great innovations occurred when Twitch said that streamers could only wear swimsuits if they were in a swimming-related setting, which prompted streamers to start addressing their audiences from inflatable pools. Twitch ultimately added an official “Pools, Hot Tubs, and Beaches” category. In this instance, it has not opted to add a Butts category.

In anticipation of Friday's TOS change, butt streaming pioneer Morgpie is currently streaming with a camera positioned under a transparent chair. “I wish people would stop complaining about the ass and enjoy it until Friday,” she said cheerfully in response to a complaint in chat.

As for what the new meta will be after Friday, she said she doesn't know. Whenever it arrives, we can be sure we'll hear once again that “content is always evolving.”