The grab to the straps was a bad move. The kitty cat would have just walked into the master bedroom without the tug. She would have set Gus down and rummaged through Luke's closet. The kitty cat, after all, was waiting. She didn't know where to go unless the Bat showed up to tell her. Not that she would ever admit to being uncertain about anything, hence all the pretense. But no, the grab made her remember where she had come from, where she had been, and Selina turned with a speed that was all unthinking Cat. She shoved her forearm against Iris' throat in the doorway, pinning the other woman against the wood. "Don't," she hissed, and it was definitely no bluff, no warning without backing to it. "I could drop you right here, and you wouldn't even see it coming. So, don't get stupid."
Unfortunately, that just made the previously-content child in Selina's arms panic, and he started sobbing and fighting to get his feet on the ground. Selina let him, because he was the lesser threat just then, and she didn't notice Gus running to the closet and then stretching on tip-toes to free the dog, not until it was too late. A growl and a snarl, that was all the warning the two women got before Finch advanced, unsure what the threat was, and only looking to put distance between the child and the women in the room. If Wren was there, she would have told both women to just back away; there was no reasoning with Finch when he was like that, not unless Luke was around.