Just look at these passages, when Emma’s falling for Léon:
“… she was full of lust, anger, hatred.” (P.2, ch.5)(For friends who haven’t read Madame Bovary: the hatred is for her husband, for being mediocre and boring, but not beating her up or giving her some other reason to hate him).
“The desires of the flesh, the lust for money and the melancholia of passion all merged in a single agony—but instead of turning her mind away she bound herself to it even more closely, stimulated by pain and looking everywhere for opportunities to indulge herself.” (ibid.)2 chapters later, Flaubert also uses the phrase “carnal desires” (in Christopher Moncrieff’s translation).
At this point, Emma hasn’t had an affair yet, but today her behaviour would most probably be called micro-cheating, whatever that means.
“She could make out tiny gold flecks in his eyes, fanning out round his black pupils, and could even smell the pomade that made his hair shine. Then suddenly she felt weak, she remembered the Vicomte who had waltzed with her at La Vaubyessard, and whose beard gave off the same scents of vanilla and lemon, and instinctively she half-closed her eyes in order to breathe it in. But as she did so she sat up in her chair, and saw the old stagecoach Hirondelle on the horizon, coming slowly down Les Leux hill trailing a long plume of dust. It was in that same yellow carriage that Léon had so often returned to her; and it was on the same road that he had left forever! She thought she saw him at his window opposite; then everything became confused, the clouds passed; it was as if she were still waltzing in the Vicomte’s arms in the light of the chandeliers, and Léon wasn’t far away, he was coming… and yet she could still sense Rodolphe’s head beside her. The sweetness of the sensation found its way into her old desires, and like grains of sand in the wind they whirled round in the delicate waft of perfume that was spreading through her soul.” (P.2, ch.8)All the men blur together. It’s obvious that what Emma needs, and wants, is some good sex, which she doesn’t get from her husband.
Just go back to the beginning and look at this scene of Emma and Charles before they get married:
“She got a bottle of curacao from the armoire, reached down 2 small glasses, filled one to the top, put almost nothing in the other and then, having clinked it with his, lifted it to her mouth. Since it was virtually empty she had to tip her head back to drink; and in that position, with her lips extended, neck craning, she laughed because she couldn’t taste anything, while between her shapely little teeth the tip of her tongue gently licked the bottom of the glass.” (P.1, ch.3)Her sensual nature has been hinted from the start.
It becomes clear that Emma craves sex. She fantasises about the Vicomte, then falls for Léon; after Léon, she quickly succumbs to Rodolphe’s seductions, then she also gets over him, and starts a new affair with Léon.
With Rodolphe, she has sex with him the 1st time they ride horses together, and during the affair, sneaks out of house several times a week to be with him.
“1 morning when Charles had left before dawn, she was seized by a sudden desire to see Rodolphe that very second. […] The thought made her breast heave with lust…” (P.2, ch.9)And then:
“All winter, 3 or 4 times a week, he came to her garden when it was completely dark. Emma had taken the key out of the gate, and Charles thought it had been lost.Note: “consumed with impatience”.
[…] To let her know he was there, Rodolphe always threw a handful of sand at the shutters. She would jump up; but sometimes she had to wait, because Charles had a habit of chatting by the fire and would go on ad infinitum. She would be consumed with impatience; if they would have done, her eyes would have leapt out of the window.” (P.2, ch.10)
Later, when Emma meets Léon again, after 3 years, she has “an irresistible urge to put her lips to” his cheeks (P.3, ch.1). She arranges a meeting in a church, which leads to the famous carriage scene:
“Among wagons and barrels at the harbour, in the streets and at the marker stones, local people stared in amazement at this unheard-of thing for a provincial town, a carriage with its blind pulled down, and which kept reappearing, more tightly sealed than a tomb, pitching and tossing like a ship at sea.” (ibid.)What a scene indeed. Subtle, but masterfully suggestive.
Later, Flaubert is plain about Emma’s high libido. Just look at these lines:
“… she came back more voracious, more impassioned than before. She would undress violently, ripping the laces of her corset, which slipped over her hips like a snake. Tiptoeing in bare feet she would check the door was locked then throw aside her clothes in a single movement—and pale, silent, serious, she collapsed into his arms with a shudder.” (P.3, ch.6)The detail I find interesting is the effort Emma makes to see Léon: “she never lost the distinct sensation of having a long way to go.” (P.3, ch.5) Emma lies about taking music lessons, in order to see Léon every week. So how far does she have to travel? The Bovarys live in Yonville, Léon lives in Rouen—the distance, Flaubert says, is 24 miles, or 38.6 km. That is about the distance from Leeds, where I live, to York—I’m lazy to travel to York by train (for the Aesthetical Short Film Festival, for instance), Emma travels by carriage. Imagine the time and effort.
Note that Emma is the one travelling to see Léon, not the other way around, when it is easier for a man to travel (19th century). That shows how much she craves sex.