Derek maintains the kiss as Eva responds. He is pleased by, and responds to, the basic nature of her desire, glad that her desire is not deeply connected to any sort of fetish ritual or similar kink, as is so often the case both with intelligent and creative people and those who have suffered trauma. Not that Derek feels there is anything wrong with that sort of desire - as long as all involved are consenting, it's cool with him - but simply because he appreciates the simple, direct, primal sort of desire she feels at that moment, one which resonates strongly with the spirit of Spring to which he is dedicated. He feels her breath and her lips become warmer and feels a warmth spread through her body, which he takes as passion and arousal. Still he simply holds her close as they kiss, not ramping up the level of physical contact yet, wanting to let Eva's passion and desire continue to build for awhile. He also doesn't say anything; there's no need for words at this moment, as they communicate in a more basic way.
When he finally breaks the kiss, he does so only to move his mouth near her ear, kissing her cheek along the way and very lightly flicking her earlobe with his tongue. At the same time, he pulls her body tight to his, letting her feel the evidence of his own building excitement.
Glancing around without breaking contact, Derek still wasn't sure whether this place was just Eva's studio, or whether she also stayed and had a bedroom here. He doesn't noticed an obvious bedroom, and is considering asking, but then he notices a large, comfy-looking couch over in the corner. Kissing his way back to her lips, he leans her backward a bit so he can kiss down her chin and neck to the hollow of her throat. At the same time, he slides one hand up her back and the other down the curve of her backside - letting it linger there a bit - then lower to her thighs. Wrapping both arms around her body, he stands straight, lifting her into his arms. Still kissing her neck, and carries her to the couch, where he turns around and sits, settling her sidesaddle in his lap.