"She's not here to be annoyed with me about my various descriptions," he responded rather annoyed. To be honest, he really didn't give two shits what Lavender would think at this point, because she wasn't here anymore so what in the bloody hell did it matter? She was back home, living her life the way it was supposed to be. Well good for her then, it was probably better than being stuck in this place with him, regardless of how happy she made him. Rabastan didn't deserve it, and Lavender deserved better.
"I don't particularly feel like being anyone's pet project," he told her pointedly, taking another drink and rolling his eyes at her this time. He wouldn't admit it right now, but he actually didn't mind the conversation of another person. He had never particularly liked being alone, but he did it more out of necessity in his life than anything else. After all, he tended to get people he cared about hurt, so the best thing to do was put as much distance between himself and them as possible.
"Well now, since I've been properly scolded and told off I'll try to be on my best behavior for the rest of the evening. If that's what you were after, rest easy knowing everyone is safe from my emotional outbursts for the night." Taking another puff of his cigarette and putting his face in his hands momentarily he added, "Looks like your job here is done." At least, he figured that's all she had been looking for.