[Her tongue has just brushed against his in the most polite way possible of course when she hears the pop of confetti above them. Realizing it's over, she pulls back slowly rather than in haste. She doesn't want him to think she's fleeing from him after all, though she wonders if that might actually make him more comfortable.
There is a light blush to her cheeks when she pulls back. It is more of embarrassment than anything. The kiss may have been just slightly awkward. If we change the meaning of slightly to imply a huge quantity.]