Last week, Instagram took a shot at Twitter by cutting off Twitter cards support, which basically meant that Instagram photos posted to Twitter appeared less-than-optimal when expanded in users’ streams. It’s clear that Instagram wants Instagram users to use Instagram – to stay inside their walls. CEO Kevin Systrom said that it was “the correct thing for our business to do at this time.”

But he also said that Instagram would always stay integrated with Twitter. Apparently, things have changed.

Instagram has, for the moment, disabled photo integration with Twitter.

“Instagram has disabled photo integration with Twitter. As a result, photos are no longer appearing in Tweets or user photo galleries. While tweeting links to Instagram photos is still possible, you can no longer view the photos on Twitter, as was previously the case,” says Twitter.

What this means for the user is Instagram photos no longer show up in tweet streams when expanded. Tweets can still contain Instagram links, of course, and you can still access the photos by clicking on the links (as you’re navigated away from Twitter toward Instagram). But the photos, which used to populate Twitter’s new media-rich stream, are no longer visible.

Rooting themselves out of Twitter completely doesn’t seem like a very smart idea for Instagram, as it will only diminish the motivation for users to share their photos across other social networks. Instagram wants you to come back to Instagram to view photos, but this seems like a drastic play for that outcome. Then again, if Instagram is truly serious about being a standalone social network, this is the ballsy move to make.

But in the end, it’s users of both services that suffer from this little spat. Having Instagram photos in your tweets stream was nice – while it lasted.

Twitter is probably going to roll out their own photo filters before year’s end. With that move, Twitter could easily adopt a “don’t let the door hit you on the way out” policy with Instagram.