I read French Literature at university, and one of my favourite authors was Victor Hugo. His writing is so poetic and impassioned; it was a real inspiration to me. Here is how he describes the first kiss of Marius and Cosette in Les Misérables. It takes place in a garden at dusk, after Marius, ‘beside himself with love’, has spilled out all his feelings.

She took his hand and laid it on her heart. He felt the paper there, he stammered:—

‘You love me, then?’

She replied in a voice so low that it was no longer anything more than a barely audible breath:—

‘Hush! Thou knowest it!’

And she hid her blushing face on the breast of the superb and intoxicated young man.

He fell upon the bench, and she beside him. They had no words more. The stars were beginning to gleam. How did it come to pass that their lips met? How comes it to pass that the birds sing, that snow melts, that the rose unfolds, that May expands, that the dawn grows white behind the black trees on the shivering crest of the hills?

A kiss, and all was said.

There is so much unsaid between them – they do not even know each other’s name – but this kiss says everything that matters; and afterwards:

Little by little they began to talk to each other. Effusion followed silence, which is fulness. The night was serene and splendid overhead. These two beings, pure as spirits, told each other everything, their dreams, their intoxications, their ecstasies, their chimæras, their weaknesses, how they had adored each other from afar, how they had longed for each other, their despair when they had ceased to see each other. They confided to each other in an ideal intimacy, which nothing could augment, their most secret and most mysterious thoughts. They related to each other, with candid faith in their illusions, all that love, youth, and the remains of childhood which still lingered about them, suggested to their minds. Their two hearts poured themselves out into each other in such wise, that at the expiration of a quarter of an hour, it was the young man who had the young girl’s soul, and the young girl who had the young man’s soul. Each became permeated with the other, they were enchanted with each other, they dazzled each other.

Such intimacy, created by that kiss. In ancient times people believed that the soul was carried on the breath, and thus a kiss was a connecting of souls. Here, it is as the poet Percy Bysshe Shelley wrote: ‘Soul meets soul on lovers’ lips’.

The first kiss is one of my favourite moments to write in a novel, and each time it’s a different experience. In Aphrodite’s Tears, for example, Oriel and Damian’s first kiss is extremely passionate and sensual, heightened by the fact that neither knows each other and the whole liaison has a dream-like quality. In my latest novel, Concerto, though, the heroine, Catriona, is just eighteen, and the first kiss is gentler and sweeter:

‘Caterina …’ he whispered again, taking her chin between his thumb and forefinger and tilting her face up towards him.

She was trembling as if in frost, as if in a fever, unable to control her own racing blood. ‘Umberto …’ she said huskily.

He reached out and lifted the heavy fall of hair, letting his hand stroke her neck and round to her throat, caressing the delicate line of her jaw with his thumb, making her shudder as her legs almost curled under her.

Umberto bent his head towards her, touching her mouth with his in a kiss as light as a drifting feather, and Catriona learned that the lips she had thought sensuous were everything that she had never allowed herself to imagine.

Umberto’s hand moved again under her hair, clasping the nape of her neck, pulling her towards him as his kiss deepened, lengthened and possessed. Letting his hands slide the length of her body to her hips, he moulded her against him in a slow sweet fusion that made her thrillingly aware of his desire for her.

‘See the effect you have on me,’ he whispered as they pulled apart, his eyes glittering with almost stunned surprise as though searching hers for an answer she did not possess.

‘I’m sorry, I’ve never …’ her voice trailed off, too embarrassed to admit that no man had kissed her before, let alone a kiss that left her whole world reeling.

‘Each kiss a heart-quake,’ wrote Lord Byron, and that is how I envision the first kiss in each novel I write. It needs to leave the couple reeling. It needs to spark an awakening in them, a flame that won’t be put out. It needs to be The Kiss, the one that will define them, the one they’ll never forget… the one where soul meets soul.