There are a number of things one could say about the Philadelphia Flyers, but let's keep it simple and roll with this: they know how to win in Pittsburgh. They also know how to flaunt this fact very, very well.
It's always nice to have home ice advantage, isn't it? And if anywhere outside of Philadelphia could be the Flyers' second home, it's Pittsburgh.
The last time the Flyers lost in Pittsburgh was... oh... all the way back on Mar. 23, 2013. And it was an overtime loss, too, so the Penguins couldn't even beat the Flyers properly. The last time the Penguins had a regulation win over the Flyers on their own ice was April 20, 2012, during that insane playoff series the Flyers ended up kicking ass in.
That was nearly four years ago. It's been that long since the Flyers visited Pittsburgh and didn't come away without at least a point (their last regular season regulation loss there was April 7, 2012, so not that far off).
As of right now, they have five straight wins over the Penguins in Pittsburgh. Seven straight with at least a point.
So yeah, home sweet (second) home indeed.