Ask any author what the most difficult part of a novel is, and the answer will likely be not the closing line or plot, but penning a convincing sex scene. From Madame Bovary to modern day Mills & Boon classics, novelists have for centuries attempted to capture the essence of lust, passion, uncertainty and sheer adrenaline that sex conjures up, with varying levels of success.

Below, we look at some of best, worst and most surreal excepts from sex scenes that literature has had to offer over the ages. Prepare yourself for some obscure metaphors, explicit language and all-round hanky panky...

"He had lifted her skirts as she stood with her back to the wall and now had his fingers between her legs. 'Come to me,' she whispered, her breath hot in his ear.'Into me now.' He removed her fumbling fingers from his trousers and freed himself … "

Photo from BBC One adaptation of Birdsong

"He laid his hand on her shoulder, and softly, gently, it began to travel down the curve of her back, blindly, with a blind stroking motion, to the curve of her crouching loins. And there his hand softly, softly, stroked the curve of her flank, in the blind instinctive caress."

"I turned the light off. I pressed against the Object. I took the backs of her thighs in my hands, adjusting her legs around my waist. I reached under her. I brought her up to me. And then my body, like a cathedral, broke out into ringing. The hunchback in the belfry had jumped and was swinging madly on the rope."

"The ensuing romp so excited Trafford he nearly fell out of the wardrobe, knocking over a canvas. Furiously Jonathan kicked the door shut. But by this time Sophy was too excited to notice. Later, as she ecstatically cradled a snoring Jonathan to her breasts, she wondered if she’d dreampt it, or had a man really slithered out across the floorboards?"

"They were beyond the present, outside time, with no memories and no future. There was nothing but obliterating sensation, thrilling and swelling, and the sound of fabric on fabric and skin on fabric as their limbs slid across each other in this restless, sensuous wrestling..."

"The wind thrust between her legs, its icy blast displaced by solid warmth as he covered her like a dog. The thing inside her jerked and threshed, a rising salmon, plunging home to spawn. 'Yes!' she shouted, relishing the scarlet pain in her knees as he kept grinding them against the barnacled surface of the groyne."

"That night she cradled me in her arms and soothed me; told me what I needed to be told; strengthened me. On that night of 12 May 1994, I needed that love Cherie gave me, selfishly. I devoured it to give me strength. I was an animal following my instinct."

"When she and Victoria had done it, it had been like trying out some strange Japanese cuisine, something that wriggled, still alive, in a dish. Or having to swallow the contents of a bearded mussel attached to a rock, while all the while one knew the tide was rapidly coming in. She was never going to be a lesbian. Being heterosexual was already strange enough."

"He raised himself to his knees and bent to roll his tongue around her weeping orifice. He was bringing her to a pitch of ecstasy when she heard Madame Veuve, on the landing, put down the supper tray. Whiffs of onion soup strayed over them as he engulfed her. 'Don't stop,' she clamoured; she was nearly there, it was in the bag."

"She felt strange and wild. Her body was just a collection of organs. She was blood and plumbing, like any other creature, and there was nothing that was forbidden about any of it. She gnawed on Tomasso ravenously, like an animal plundering a carcass, and when she had had enough of that she swung her leg over him, like a rider swinging into a saddle, and galloped."

"The cloth of her habit caught against the velvet of his coat. She threw back her white neck, swelling with a sigh, and faltering, in tears, with a long shudder and hiding her face, she gave herself up to him."

"It is time, time ... Now. Yes. She is so small and compact and yet she has all the necessary features ... Shall I compare thee to a Sony Walkman, thou art more compact and more - She is his own Toshiba, his dinky little JVC, his sweet Aiwa ... Aiwa, aiwa aiwa aiwa aiwa aiwa aiwa aiwa aiwa aiwa aiwaaaaaaaaahhhhhhhhh ..."

"She had never undressed like this before. The shyness, the feeling of inner panic, the dizziness, all that she had always felt when undressing in front of the young man (and she couldn’t hide in the darkness), all this was gone. She was standing in front of him self-confident, insolent, bathed in light, and astonished at her sudden discovery of the gestures, heretofore unknown to her, of a slow provocative striptease."

"I kissed his mouth ravenously, devouring his neck, earlobes, chest. He broke free with muscular ease, unhooked my bra with composed expertise, found my nipple and flicked his tongue back and forth until it went hard. His towel fell away. Sebastian's erect member was so big I mistook it for some sort of monument in the centre of a town. I almost started directing traffic around it."

"She went lower, her hands and lips - multiple mouths - taking possession of me, not giving what I wanted, but offering urgent promises. She anticipated what I wanted, which was a pleasure beyond desire, something like a refinement of gluttony, sucking the life from me, all the while soothing me with a satisfied purring in her throat."

"The silken heat of her drove him to the brink. He managed to stave off his own satisfaction only by focusing every ounce of his thoughts on her. Her needs. Her wants. Ignoring the heady scent of floral fragrance and warm woman, Nathan concentrated on finding just the right touch that would please her, make her forget her own name."

"The smell of his armpits was on her shoulders - a flower depositing pollen on a hummingbird's forehead. They detonated the remains of each other's orgasms with fingers and tongues, areas of their bodies sticking together with sweat that was like the weak glue that holds segments of an orange together."

"There was something about her eloquence at that moment and the way she thrust that rose­bush under my nose which remains unforgettable ... Her words imbued it with a peculiar fragrance; it was no longer just her private organ, but a treasure, a magic, potent treasure, a God-given thing - and none the less so because she traded it day in and day out for a few pieces of silver."

"She gripped my arms. Her nails tore into me. Soon we both were burning. Sweat pooled in the ridge of my back as I moved like a tide determined to crash against those ancient rocks. Then – a moment before – inside, I kept very still. Our bodies moved of their own accord."

"He held her by the hip and strained up to her, rising off the bed and reaching in her, saying Megha, and she rolled down to meet him, and at the closest point of their meeting he felt the spill, ecstatic and alive, and in a last moment of thought he asked, is this me? Is this you?"

"'Love me!' she moaned lustily. 'Oh, Ward! Love me now!' He jumped out from his pajama pants so acrobatically it was like a stunt from Cirque du Soleil. But when he went to remove her slip, she said, 'Leave it!' which turned him on even more."

"He had complained that Heaven had cast him off, but now the whole breadth of heaven leaned low over his bed, holding out two strong, white, woman's arms to him. His head swimming with joy, he drifted into happiness, as though losing his senses."

"Had she pulled on the wrong thing? Had she gripped too tight? He gave out a wail, a complicated series of agonised, rising vowels, the sort of sound she had heard once in a comedy film when a waiter, weaving this way and that, appeared to be about to drop a pile of towering soup plates."

"He pulled down her brassiere, cupping her breasts, sighing in bliss. 'The blue veins are divine,' he whispered. At that moment, a lifetime of unease about this ugly feature of her body was replaced with satisfaction. He licked them, circling her nipples hungrily. Then he disappeared up her skirt."

"Suddenly he heaved himself over between her legs, fumbled himself into her, thrust away a few times - no more than six at the outside - and then, with a terrific gasp to tell her that it was now (which she countered with some cries and pants of her own), he collapsed on top of her. The whole business, from the moment he folded the paper, had taken perhaps eight minutes."

"He touched her neck, the softness of his fingertips raising tingles along her skin and spreading throughout her body, bringing a spike of pleasure to her centre. 'What kind of spell have you cast on me?' she asked, her voice barely above a whisper. 'The same kind you've cast on me.' His fingers moved up to her cheek, softly caressing the hardened scars left by the wolves' vicious bites."

"Very slowly and gently, he undressed her, covering her white skin with kisses while he caressed her back. To her complete astonishment, she felt herself becoming aroused. 'Shhh, shhh ... ' Marcus was brushing her breasts with his fingertips, all the time shushing and stroking her like a groom reassuring a frightened foal."

"'Oh Jesus. Yes!' he gasped as her lips and teeth closed savagely around him and he felt the tip of her tongue poking and probing. Then, just when he was beginning to think that he must explode, her mouth was gone and in its place he felt her hands once more and he smelt the unmistakable smell of oiled rubber."

"I had it now, I felt it now, and, beginning to drive, he soon gave nature such a powerful summons down to her favourite quarters, that she could no longer refuse repairing thither; all my animal spirits then rush'd mechanically to that center of attraction, and presently, inly warmed, and stirr'd as I was beyond bearing, I lost all restraint"

"Jordan Groves and Vanessa Von Heidenstamm did not notice the approaching darkness. They were still immersed in their lovemaking. It had begun slowly, tenderly, face-to-face, with long, lingering looks at each other, like devoted siblings at the start of a long absence ..."

"It was Heaven. I was the earth, the mountains, the tigers, the rivers that flowed into the lakes, the lake that became the sea. He was thrusting faster and faster now, and the pain was mingled with pleasure, and I could have said: 'I can't take any more', but that would have been unfair, because, by then, he and I were one person."

"She was musical and apple-sweet. Her legs twitched a little as they lay across my live lap; I stroked them; there she lolled in the right-hand corner, almost asprawl, Lola the bobby-soxer, devouring her immemorial fruit, singing through its juice, losing her slipper, rubbing the heel of her slipperless foot in its sloppy anklet, against the pile of old magazines heaped on my left on the sofa — and every movement she made, every shuffle and ripple, helped me to conceal and improve a system of tactile correspondence between beast and beauty — between my gagged, bursting beast and the beauty of her dimpled body in its innocent cotton frock."

"She confiscated the zapper and slid my hand between her thighs. It was wet and warm down there, which was only to be expected, but she might just as well have deposited my hand on a pizza for all the effect it had."

"Slither slither slither slither went the tongue, but the hand that was what she tried to concentrate on, the hand, since it has the entire terrain of her torso to explore and not just the otorhinolaryngological caverns - oh God, it was not just at the border where the flesh of the breast joins the pectoral sheath of the chest - no, the hand was cupping her entire right - Now! She must say "No, Hoyt" and talk to him like a dog ... "

"She is topping up your engine oil for the cross-country coming up. Your RPM is hitting a new high. To wait any longer would be to lose prime time... She picks up a Bugatti's momentum. You want her more at a Volkswagen's steady trot. Squeeze the maximum mileage out of your gallon of gas. But she's eating up the road with all cylinders blazing."