The first part of Donna's story is perfectly normal, and he expects to end with some arsehole using her and screwing her over, which is about par for the course with men, in Crowley's experience.

Then she starts talking about spider-people, and his eyebrows get higher and higher as he tries to wrap his head around it. Sure, he's a demon that's older than time itself, but he's used to that. Aliens are kind of new. Spider-people are kind of new. It's all a bit weird.

The basics are still the same, though, and once he gets over the weirdness, once Donna gets to sorry that happened to you, his face does something complicated, because he's not used to — empathy, when it comes to this. It doesn't really matter that he wasn't telling the entire truth, what she says still hits close enough to make him feel Some Kind Of Way about it.

So he does what any well adjusted person does when faced with unfamiliar emotions, and shrugs. "S'fine, really, it wasn't that big of a deal. Not half as shite as someone trying to turn you into an incubator. Sounds like he'd have had a great time in a place like this." He's not gonna mention that he's tied to the Web. He has enough tact for that.