Gwen had already made her mind up. Before she had even vomited she knew that she wasn't going back inside without him. Peter wasn't in any shape to fight against anything anymore. He wasn't doing well emotionally or physically. He was hurt and he was upset over Lydia. It didn't take a Valedictorian to put those clues together. An idiot could have told what was going on with him. He'd lost his friend, or whatever she was to him, and that had to be hard. Gwen didn't understand exactly how he felt, but she could empathize. She understood what it felt like to lose someone that you cared about.
Feeling him tense, Gwen didn't move her hand, leaving it where it was settled. His voice wasn't his own, really. He didn't sound like himself. It was almost like a stranger was talking to her. All Gwen could manage for a moment was a shake of her head, her other hand reaching to touch his face. "I can't leave you out here alone." She told him softly. She meant that.
He had to come inside. If she left him here there was just too much chance that something might happen to him too. She didn't want to lose another person that she cared about. If he refused to come in she'd wait out here with him and if he wanted to bring Lydia in...she'd help because she cared about Peter. No matter what, she wanted him to come inside, though. He was in no shape to fight now. She was pretty sure no one would have argued that point with her right about now, save maybe Peter himself. And she wasn't even sure if he could muster that up at the moment.