Any time Will and Gabriel open their mouths in each other's presence, really.
- Tessa, meeting Gabriel for the first time:
"I," said Gabriel, "would rather have my entrails yanked out and tied in a knot in front of my own eyes than apologize to such a worm."
"Gracious," said Jem mildly. "You can't mean that. Not the Will being a worm part, of course. The bit about the entrails. That sounds dreadful."
"I do mean it," said Gabriel, warming to his subject. "I would rather be dropped in a vat of Malphas venom and be left to dissolve slowly until only my bones were left."
"Really," said Will. "Because I happen to know a chap who could sell us a vat of-"
- And later, after the raid-gone-wrong on the vampire house.
"Nice work in there, Herondale, setting the place on fire," Gabriel observed. "Good thing we were there to clean up after you, or the whole plan would have gone down in flames, along with the shreds of your reputation."
"Are you implying that the shreds of my reputation remain intact?" Will demanded with mock horror. "Clearly I have been doing something wrong. Or not doing something wrong, as the case may be." He banged on the side of the carriage. "Thomas! We must away to the nearest brothel! I seek scandal and low companionship."