Luna didn't even attempt to pretend that she wasn't utterly delighted (and turned on) by his reaction, and she pushed herself backwards on the bed, away from his advance.
"I'm so sorry," she said, in the tone of someone who was not even slightly sorry. Fuck, she wanted to be kissing Merlin right now, her eyes flicking hungrily down his body as his clothing disappeared. To match him, Luna reached behind her back with one hand and undid her bra, though didn't yet remove it. "I'm terrible, don't know why you'd put up with me."