It's a lovely mix of PLEASE GO AWAY and Dorian actually kind of liking her company. Because Didi? Didi's pretty swell. She's good for a conversation, he enjoys talking with her, she seems like a lovely lady who he could possibly be surface level friends with. But Didi's also Death. And Dorian has so many hangups about death namely the fact that a: he doesn't want to die and b: when he did die, it SUCKED. So she'll occasionally say some very Death-like things and nope, that pleasant conversation is just straight up ruined in Dorian's mind now.