Jacob did not let go of Bella. It was nearly impossible to do once she was in his arms and not pushing him away. He knew Seth's how as well so keeping Bella to him, he answered. "SETH!" His voice was louder than Leah's so he kept Bella against his chest muffling the noise. If push came to shove, he knew he could phase and they could speak but he didn't want to lose his Bella again.
"I can't see him," he said to Leah, but at least we know he was here. "One of us could duck out of sight and howl back." He wasn't sure being a werewolf out in the open was a good idea but maybe Leah would take it up, leaving him free for his girl.