Lee has to let go of his hand so she can put both of hers over her face, which is now the same shade as a tomato. She's so easy to embarrass, even innocuous things can send her running off to hide. But she's still giggling helplessly, or even moreso now, nervous laughter even though they've been dating two years and doing it almost as long.
It's about this moment (probably the most innocent) that their waiter returns with their food and sets both plates down as discreetly as possible. He's probably realised they're both celebrating something important, and has seen enough amorous couples to know how to act. Lee starts on her second glass of wine. Her head is ducked down, hair over her face like a veil.