It took a day and a half for Stella to relax enough to solicit play and Pongu to warm up to her enough to engage (and he still isn't that warm, although he will tolerate her presence as long as she doesn't try to get up on the couch where Only Pongu Is Allowed), but it looks like the pancake dog has officially been welcomed into Team Stupid.
Now I get to have constant bumfights next to my computer while I'm trying to work again. Hooray.
Afterward Stella was totally pooped out, and when I put her back in her crate, she just snored all night long. I have never seen a dog snore that loudly for that long. I tried to tape it but the camera didn't begin to do justice to the loudness of her snores (also Pongu was not excited about me paying attention to Other Dog again and photobombed me nonstop).
It's only been two days, but I want to keep this dog. If I keep the dog that means no more fostering, though, and that would make me sad. :[