“I'm not grumpy,” Sita said, looking down at the table. But she really wasn't. Uncomfortable, yes. A bit freaked out by everything, yes. But she wasn't actually grumpy.
This woman did make a good point—she was at a party and she should be having fun—and she had sort of had fun, briefly, when she'd talked to that vaguely weird guy from her class who'd been dragged here along with her. But, frankly, she wouldn't mind just getting out of here if she could figure out how. Which she couldn't right now. She couldn't even figure out how to get away from this woman.
So she looked back up and said, in what she hoped was a cheerful voice, “The food is good!”