"If he moves, kill him." The words followed the awestruck Sin into the nursery, Lust's frustration and fear of what harm her brother's hand's could wreck before she might have the opportunity to stop him outweighing all else. She didn't have the Hellfire, she didn't have the strength and ability to stop him by herself if he really tried, something she was woefully aware of.
Whether she couldn't figure out this new presence in their home, picking up on her mother's distress or just general fussiness, the child that shouldn't have been only became more discontent, and therefore louder. Seething in irritation at being ignored, and the general upset of her household, Lust edged by her brother warily, waiting for the slightest hint of movement that would give her cause to end the threat where it stood in her daughter's nursery.
Familial bonding was forgotten entirely in light of the prospect of making a display and providing a cautionary tale for any future attempts on the child's existence.
Awkwardly reaching out for her daughter, Lust tried her best to angle her away from Gluttony, putting as much distance between the two as humanly possible in the too crowded room, while trying to somehow comfort her to reduce all of the damned noise. The last thing she needed was Des to come wandering by to figure out what in the Hell was going on, and if it took actually touching it, and holding it, then so be it.
"It's time for you to go now. Send the others if you want, but they'll not get the warning you did. From here on, it's kill on sight, I won't let anyone hurt her." Lust's words were simple, and she fully meant everything she told her brother. Pressing her cheek to her daughter's downy head, she tried to shush the agitated baby, while her eyes remained cut dangerously on her brother.