Sly Without the Swear
Three tells that make a Malfoid line land late.
1. The backhanded compliment: it reads as praise and lands as a cut. "I love that you got to eat that - you really looked like you needed it." On the surface it is kind. Underneath it is a knife. The compliment is the cover; the cut is the message.
2. The over-airy "oh": a single word with just a fraction too much air in it. "Oh, you still do that." The cut is not in the words - it is in the breath. That is why the volume has to stay down: if she raises it, it becomes a tantrum, and tantrums do not sting an hour later.
3. The delayed sting: the sentence has to sound fine while it is being said and only go wrong when you replay it. "That is a very specific choice - in a good way." The "in a good way" is the tell. It is the softener that is not a softener, the one that makes you second-guess yourself after she is already gone.