Animals, or rather all living beings, are predominantly driven by their sense of smell, with over 80% relying on it.
Genetic makeup determines one's perception of scents, whether pleasant or unpleasant. For instance, dogs find feces appealing, while cats prefer rotten fish over fresh.
Even among humans, preferences vary. Some people find the smell of feces repulsive but seek out similarly pungent foods, like fermented seafood or canned sardines.
Taste, being part of the nervous system, can influence the entire brain and other neurons.
For many animals, the signal for mating is conveyed through scents, and potential mates judge each other's readiness through these olfactory cues.
During genetic modification, some human scientists exchanged unclear gene components, turning Xu Bin into a walking aphrodisiac.
Not that anyone would get aroused just by being near him, but during moments of excitement, his body secretes a unique signal through sweat, enticing others into a state of arousal.
This enhances their pleasure and makes it easier to achieve climax, though the effect is more pronounced in certain individuals.
Genetics vary from person to person, and uncovering the human genetic sequence is a complex and vast endeavor.
Currently, this is only targeted at Yao Nan, and the side effect is that women related to her by blood are more strongly affected.
During intimacy, even foreplay or kissing can be incredibly sensitive and pleasurable. For other women, the effect is less noticeable.
Xu Bin was thrilled by this unexpected benefit, impressed by the system's intelligence.
His beautiful mother-in-law's breathing slowly returned to normal, but she kept her eyes closed, too embarrassed to open them. Xu Bin's hands continued to explore her large, voluptuous breasts.
Regaining his composure, he leaned in to lick her sensitive ear, then guided her hand to his lap, panting, "Mom, you're enjoying this, but I'm still hard and aching."
Shen Ruyu finally opened her eyes, a hint of worry in her voice, "Why haven't you... finished yet?"
"You think I'm some quick shooter? No way," Xu Bin chuckled, licking her lips teasingly, "What, Dad doesn't last long?"
"Stop asking so many questions!"
"Come on, Mom, just tell me."
After experiencing the pleasure of oral sex, Shen Ruyu's voice took on a sultry tone, her previous protest sounding almost like a flirtatious tease to Xu Bin's ears.
"About... three minutes," she panted, stroking him anxiously, "You should hurry up, what if Nan wakes up and needs to use the bathroom? Pregnant women get up a lot at night."
"Don't worry, Mom, I've got a plan," he kissed her cheek and quickly left the room, returning with a change of clothes and shoes that Yao Nan had prepared for him.
Lately, Yao Nan had been incredibly thoughtful, taking care of all his needs. Xu Bin didn't even know where his own clothes were; she managed everything.
"If Nan can't find me, I'll just say I went to the internet cafe for a bit," he locked the door behind him, and on the bed, his mother-in-law lay, her body radiating a seductive allure. Her eyes, filled with desire, and her bitten lip seemed to beg for more.
Xu Bin pounced back onto the bed, and this time, Shen Ruyu initiated the kiss, pressing her body against him, allowing him to explore her breasts while she stroked him, one hand on his shaft, the other caressing his testicles. The sudden intimacy was almost too much for Xu Bin to handle.
Their kiss was passionate, and Xu Bin found himself at her breasts again, mumbling, "Mom, you're just as wet as Nan, no wonder she's your daughter..."
"When she climaxed after I licked her, she didn't produce as much fluid as you."
"You little beast... stop teasing me," Shen Ruyu huffed, her cheeks flushed with embarrassment.
"Mom, your body is amazing... Nan doesn't have your curves," he complimented, his hand moving between her legs, gently teasing her wet, shaved mound.
She moaned, her breath hitching as she struggled to keep her cries of pleasure quiet, no doubt embarrassed to be caught in such a compromising position with her son-in-law. Xu Bin couldn't wait to see how unrestrained she would be when they were truly alone.