Word or phrase for sudden fast breathing not caused by physical exertion

I am writing a story and I am at a loss for a word/phrase. The scene is as follows:

Two young people have fallen in love with each other. They are doing a slow dance and suddenly get too close to each other. They breathe in a fast manner. What is this type of breathing called? What is the word/phrase for this?


Solution 1:

In the extreme you could use "they started to hyperventilate." Can you provide some of the sentences you have so far so we can be more helpful in context?