The worst partners often make the best lovers. I don't mean skilled. I mean unforgettable. The kind we still think about years later, even though we know we shouldn't.
I used to believe that was how life functioned: toxic people, great sex, and a kind of magical exchange. However, I was mistaken. Or at least, only partially correct.
What I've come to understand is that the intensity has nothing to do with the person and everything to do with three engines running beneath the surface. Once we notice them, we won't be able to ignore them anymore.
Engine One: We Cannot Predict Them
Have you ever been in a relationship society calls toxic? The kind that felt like a roller coaster and made you feel like a crackhead? Most people I know have, at least for a few months. And nearly everyone agrees on one thing: the sex was incredible. Those people often sit comfortably in your top three.
This was my previous belief: toxic people must be very good in bed, deliberately so, to keep us hooked. That was my first instinct back when I was in a relationship like this.
Almost a decade later, I'm second-guessing it.
Maybe a subset of them do it deliberately. But something else is going on. Something that runs whether anyone is steering it or not. Once you understand what it is, the cheaters also become understandable.
Toxic relationships often revolve around a concept called intermittent reinforcement. I’m not crazy about clinical terms, but this one is really worth understanding.
Our brains release more dopamine in response to unpredictable rewards than to predictable ones. This creates a cycle similar to addiction, in which we become obsessed with the next "high". We endure pain because we believe a positive experience is imminent, constantly chasing that fleeting satisfaction. The pattern of ups and downs, like "shit - shit - joy", triggers a stronger addictive response than long-term calm and happiness, such as "peace - peace - peace - joy".
At first glance, that seems backward. But it makes sense once we know where dopamine enters the story. The chemical isn't released when the reward arrives. It appears in the gap between expectation and outcome, in what neuroscientists call the prediction error.
Think about rain. When it rains every day at 4 pm, people tend to stop noticing the sky. We grab our umbrella and go about our day, hardly giving it a second thought. But when the weather is uncertain, we're constantly checking the window, feeling it in our bones. The rain itself hasn't changed; it's us who keep waiting for it, expecting it to be different.
Now replace the weather with a person. With an emotionally regulated partner, we predict good sex, and we get good sex. The brain registers: Expected. No error. We feel content, and the dopamine hit is modest.
With an emotionally immature partner, we cannot predict anything. Is tonight the night they are warm and present, or are they distracted and cold? When they suddenly become wildly passionate, our brain registers a massive prediction error (wait, I did not see this coming) and floods us with dopamine.
We're not experiencing "wild" sex because our partner is skilled; instead, it's because our nervous system is already activated, anticipating the next peak. The sex itself isn't more intense; our brain is confusing physiological arousal with genuine sexual chemistry.
Engine Two: Our Body Doesn't Know What It Is Feeling
This is where things start to get even stranger.
Research indicates that the brain has difficulty distinguishing between anxiety, excitement, and physical attraction. Our body relies on a single alarm that it activates for all these situations.
A racing heart, shallow breaths, sweating, and that hollow feeling beneath the ribs are all responses triggered by fear, adrenaline, or craving. The body always sends the same signals, leaving it up to us to interpret them. This is a problematic division of responsibility, as our understanding depends heavily on who we are facing at the moment.
The concept is called excitation transfer: arousal lingers after the stimulus ends, influencing subsequent emotions. It’s most intense when our body is still energized, but our mind no longer blames the exercise bike. The receipt is gone, but the money remains, so it’s attributed to the current situation.
The body creates the state first, and then the mind adds the caption afterward. However, the mind is a poor journalist.
If our emotionally immature partner gives us the silent treatment for three hours, then suddenly pounces, our racing heart is half stress recovery, half lust. Our mind calls it "incredible sexual tension."
People mistake anxiety for chemistry because nervousness, adrenaline, and high alert feelings are mistaken for passion. First date nerves, fights ending in make-up sex, or relationships with unclear boundaries all stem from the body's high-energy state misinterpreted as love or passion.
Engine Three: Relief Is Not Intimacy
Two engines make us misread a night. The third one keeps us in the house.
Over time, this nervous system looping forms what is known as a trauma bond, a concept thoroughly examined by psychologist Patrick Carnes, and this bond has a specific structure:
Tension → Crisis → Explosive Relief (Sex) → Honeymoon → Tension again.
Sex is at the relief stage, which is the key. After threat and hypervigilance, physical intimacy releases oxytocin and opioids, flooding our brain. This relief is addictive, not for mind-blowing sex, but because it felt like rescue.
So yes, that is why reconciliation sex is amazing. The fight served as foreplay.
We spent three hours convinced they would leave, and our body was ready to be abandoned. When it doesn't happen, all the tension releases suddenly. That isn't intimacy; it's like a hostage being set free.
This is also why breakup sex makes people second-guess their decisions.
Breakup sex combines the usual intensity with a sense of scarcity. It's the final encounter; neither of us is bored or pretending. For the first time in months, both of us are genuine about something. Our prediction error skyrockets. Then, lying in the dark, our body delivers an unexpected verdict: something so powerful can't be meaningless.
So we go back. Not because we thought about it. Because our body decided, and we were not in the room.
Imagine the same night in a house where no one ever leaves. Without a crisis to rescue from, the sex lacks that addictive sigh of relief, and our brain, caught in the cycle, confuses the absence of withdrawal symptoms with a lack of passion.
The Part That Proves It
You don't have to take my word for any of this. The relationship runs the experiment for you.
If better sex were solely due to the partner's skill, it should improve or at least stay consistent over time. However, it often does the opposite. The "wild' side of sex usually declines once the partner feels securely attached. When someone feels they've "won" us, the element of unpredictability, often linked to excitement, is lost because the reinforcement becomes predictable. Knowing we'll stay regardless diminishes the thrill, dopamine levels drop, and as a result, the sex becomes mediocre or less frequent.
So yes, I regret to inform you that this "omg that mind-blowing sex" you recall, that I remember too, and that many friends have reminisced about, is actually somewhat of a red flag.
Nothing truly broke; the fuel just ran out. The fuel was never really about them; it was about the uncertainty of trusting them.
Same Engine, Better Neighborhood
The same excitement drives early relationship sex. Can we agree the sex in the first months is more electrifying? "The honeymoon phase." The same engine. In a healthy relationship, this lasts until we feel secure, then it gives us something else.
In a new relationship, we don't know their rhythms, turn-ons, schedule, or emotions. Our brain constantly predicts: will they text back, like this, stay the night? Novelty itself triggers dopamine because it's new... new body, smells, sounds, angles, triggering reward responses in the brain.
A third, quieter aspect is that sex with a new partner involves mate assessment. Our nervous system stays alert to check if the person is safe and compatible. This micro-alertness heightens our senses, making every touch more vivid.
In brief, the healthy one loses interest and offers something new, while the toxic one never does because it creates novelty arbitrarily, like at 10 pm on a Tuesday.
The Cheater Found a Loophole
Remember the other thing I mentioned? Here it is, featuring the same three engines in a different form.
A cheater isn't always seeking better sex; instead, they're aiming to restart the unpredictability cycle while staying securely within their main relationship. They've discovered how to create a sense of novelty without leaving their home.
Cheating is both novel and forbidden, involving secrecy, sneaking, and risky messages that reinforce the behavior. The cheater's brain receives reward from four sources: sex, novelty, risk (adrenaline), and scarcity, making each encounter feel precious and rationed.
This is the exact psychology of a slot machine. The reward is unpredictable and scarce, so the dopamine hit is exponentially higher than routine sex with a spouse who is always available.
For those who have been cheated on, understand that, from a neurological perspective, cheating can be incredibly addictive.
Cheating offers a unique combination of rewards that few other experiences can match: dopamine from discovering a new partner, their new body, and the thrill of pursuit; adrenaline from the danger, secrecy, and rarity; and opioids from the pure physical pleasure of sex.
When these three hit the brain together, they create a supernormal stimulus, a reward so potent it rewires the reward circuitry. It is the megazord of happiness.
A reward of that size creates a neural pathway. When someone cheats and receives it, their brain strengthens the link between "novelty + risk + sex" and "intense pleasure," a process known as long-term potentiation in neuroscience. Essentially, the brain invests in this shortcut, saying, "This was effective, so let's make it quicker and easier to access in the future."
I am not saying "once a cheater, always a cheater." But oh well.
Let Me Be Clear About Something
This isn't an excuse for abusive behavior. Knowing how intermittent reinforcement works doesn't justify it. Recognizing trauma bonding doesn't diminish the reality of trauma. And understanding why someone cheated doesn't mean you must forgive them.
This essay aims not to excuse anyone but to help you recognize the hook itself so you can anticipate it in the future.
Stay ethical, y'all.
What I Believe Now
This is my current understanding, nearly ten years after that relationship. The chaos wasn't passion; it was my nervous system's survival mechanism. It confused unpredictability with excitement, relief with closeness, and exhaustion with love. These three forces are real, powerful, and completely indifferent to our happiness. As long as we feed them, they will continue to operate.
But we can stop feeding them.
The initial step is recognition: realizing that the "mind-blowing sex" we recall does not indicate a deep connection. Instead, it highlights a significant disconnection between our body's survival reactions and our mind's understanding of them.
The second step is harder: learning to sit with quiet acceptance that a relationship without roller coasters isn't without passion, but without chaos. The sex and intensity will change, replaced by something quieter and more durable, not feeling like rescue since we were never in danger.
I once believed passion depended on uncertainty. Now I realize it depends on presence. Presence is not about unpredictability; it's the opposite. It's about being fully here without waiting for chaos to make we feel alive.
Choose a better neighborhood and stop confusing peace with boredom.
