Sam would have liked to believe that he could save her, that if he taught her how to draw a devil's trap and perform an exorcism, she might be able to defend herself long enough for him to get back and help. She could probably stop Brady, at least, because he wouldn't be expecting her to know any of that-- because he'd been watching Sam, and so had the other demons, and they knew that he hadn't told Jess anything that he knew about how to stop them. At that point, in fact, even he hadn't taken on a demon, so he wouldn't have known how to do any of those things. And that was perhaps the strangest part of all, to remember how very little he'd known about demons, about what was really happening, in the time that he'd been at Stanford with Jess. There had been a time when taking on one demon had seemed nearly impossible; now he had taken on whole armies of them.
At least it meant that he could do a better job of protecting her, now. Not only because he was being honest about the dangers, but because he had a better knowledge of them himself.
But for a moment, when he was kissing her, he almost forgot about the danger, about all of his fears and insecurities. Love and affection and desire had been drowned out by guilt and grief and pain for so long that it took him a little bit by surprise to feel them coming back, overshadowing everything else, just for one perfect moment. Maybe, just maybe, if he could have a few more perfect moments like that, his emotional and mental state really would start to take a turn for the better.
He rested his forehead against hers instead of pulling away entirely, one hand resting on her lower back and the other against the top of her spine where his fingers could curl gently into her hair. "You're right," he said, closing his eyes for a moment as he soaked up the peacefulness of the moment, drinking it in like a man who'd been dying of thirst. "It's true. I don't entirely trust myself, but I trust you."