The lenses of Nightwing's mask were remarkably resilient and had the added bonus of concealing his eyes from either Damian or Talia. As such they perfectly concealed the glare he was shooting the demented mother figure while his jaw clenched in frustration. Talia had wanted them to look after her kid and then had the nerve to pull a stunt like this? Where did she get off-- Dick stopped that train of thought, took control of his breathing and began running through the best method of taking Talia out of the picture.
Force was out of the question. Grayson had never known Damian to show any type of emotion other than anger and a few other related emotions but even so, he wasn't willing to bet that Damian didn't care for his mother. Maternal figures always held a special place in a child's heart, no matter how fucked up their childhood was. If he was to attack Talia, the only thing it would accomplish would be driving a bigger wedge between Dick and Damian. He'd have to use a different tactic.
"I'm here to take you home Damian." He dipped his chin to signify he had addressed his sidekick. Then he lifted his gaze back to Talia as if waiting, daring her to object.