Her heart rate had picked up, Derek noticed, as she came nearer. He could hear it thumping in his ears and, until she smiled, he couldn't tell whether it was the good sort of nerves or the bad sort, so he hesitated. The smile, though, and the way she leaned in a little further to close the gap between them sealed it for him.
The fingers under her chin moved with the rest of his hand to hold the side of her face, palm pressed against her jaw to keep her near as she deepened the kiss before pulling him closer. Derek saw that action and raised her a bolder one of his own.
Martha was small, even if he hadn't been graced with the strength of a werewolf. He let his hand fall from her face and reached for her, meaning to lift her into his lap to even out the height between them so that neither of them was craning their neck too far to accommodate the kiss that he had already sort of melted into with ease.