There are three parenting bridges I thought we’d have plenty of time to cross: drugs, dating and bullying.

I suspected bullying would rear its ugly head first, but I figured we’d at least have until kindergarten to give Henry street fighting lessons.

Turns out I was wrong about bullying. Turns out that happens pretty quickly. Like as soon as your kid can walk away from you.

Last week Henry and I crossed paths with three bullies.

The first two looked to be about eight years old. First they taunted my kid for wearing a diaper, then they threw fistfuls of rubber mulch at his head.

“Wah wah,” they snorted. “I’m a BABY. Change my diaper!”

Under their breath they whispered, “I wish he would go away.”

They didn’t know I was watching them, that I had been watching them for 10 minutes before my son even wandered in the direction of their closely-guarded mean boy space.

They radiated piss potted-ness. They scowled at their mothers and hissed at each other.

I’m not the kind of parent who hovers over my child on a playground. Consequently, I let Henry walk into this mean boy space. As usual, he was looking to make “friends,” someone with whom he could briefly dig in the dirt.

My child approached. The boys grew agitated. They cast their eyes at the ground and then at each other. They mumbled something about “dumb babies,” and retreated to a new mean boy space. Henry, however, followed. As did my gaze.

Upon noticing the toddler’s return, the mean boys made a joint decision to pick up mulch and toss it at his head. This act was followed by the aforementioned diaper comments and mock crying, prompting my involvement.

Like a mama grizzly I charged past the boys to retrieve my son, who was still, for the most part, oblivious to the taunting. Even the mulch-throwing hadn’t registered as threatening. Henry was simply curious, a bold, gregarious child, trusting of everyone and everything within his reach.

The boys looked at me with wide, fearful eyes. Their mothers were sitting on a nearby park bench, gossiping about another mother as oblivious to their sons’ actions as Henry.

I thought about ratting on the little hooligans, but reconsidered on account of THAT WOULD BE LAME. Instead I reached my hand out for Henry, urging him to play elsewhere.

“These boys are not nice,” I said. “They forget they used to wear diapers too.”

They glared at me, kicked at the ground, then mumbled something under their breath.

Henry protested. He actually liked these jerks, or at least it seemed that way based on his indifference to their abuse. I thought about leaving him there to work it out on his own, but decided that would make me an accomplice to baby bullying.

I dragged him away, wondering if two-year-olds are capable of feeling embarrassment.

“One day we’ll talk about standing up for yourself,” I said. “Right now I fight your battles.”

To which my son replied, “Lawnmower.”

The next day it happened again. This time we were at a play zone at the mall, which is where I sometimes take my kid on rainy days when our outdoor plans are thwarted and we don’t have enough cash to do something fancy. Tuesday was such a day.

I loaded Henry into the car and drove 15 minutes to a crappy mall, where I promised him we’d take a choo-choo ride on the mall train – a trackless electric train driven by a humorless man in bib overalls and a conductor’s cap.

“The train only runs Thursdays through Sundays,” the mall info clerk informed me. “Sorry.”

“Choo choo train,” Henry exclaimed. “Mama. Go.”

A clap of thunder shook the mannequins at Victoria’s Secret. Rain hammered the roof. We weren’t going anywhere for a while.

“Rainin’!” Henry said.

I grabbed his hand and headed in the direction of a play zone that’s usually run amok with toddlers and bored mothers eating cheese pretzels. Tuesday’s crowd was especially worse for the wear. One pregnant woman alternated between clawing out her kid’s eye boogers and licking what looked like an old doughnut out from under her nails. One man with a young girl looked like he was being supervised by a parole officer. Each time he reached for the girl, a woman nearby would scribble something in a notebook. When the child threw a tantrum, the man threw his hands up in the air.

“I don’t know what she wants!” He snapped.

The parole officer scribbled something in her notebook as the girl kicked the wall. The pregnant mom with the doughnut nails slurped from a bladder buster-sized soda.

Henry sat down beside a little boy who was playing with counting beads.

“No!” The boy yelled.

Henry reached once more for the beads.

“No!” The boy yelled, popping Henry in the face.

I got up to retrieve my son, who looked more shocked than hurt by the kid’s assault.

“Mama head,” he said pointing to his face.

I carried him away from the scene of the crime, casting a bitchy look at what I presumed was the child’s unconcerned mother. Again I thought about ratting on the little perpetrator and again I simply removed myself and my son from the equation.

Five minutes later Henry returned to the counting beads. The hitting boy was on the opposite end of the play zone so I figured it was safe to let him tinker with the beads, which by the way didn’t belong to the kid. They were mounted to the wall, a part of the play zone.

Suddenly, out of nowhere the hitting boy came barreling toward Henry.

“Noooo!” He yelled.

This was his only warning before clocking my son (again) in the face.

This time the unconcerned mother had no choice but to put down her cell phone, on which she was surfing Facebook, to briefly reprimand her son.

I didn’t wait to see if her half-assed scolding had any effect. We left the mall with a scratch on Henry’s nose.

As I drove home in torrential downpour I wondered when my kid had gone from a delicate flower to a punching bag.

To be clear: Henry is no saint. He, like many cretins his age, misbehaves from time to time. He’s hit the pug. He’s bit his mother. He’s thrown toys down stairs. He’s raged against the floor. Try as I may to prevent these transgressions by being a perfectly attentive parent who reads books about how to be a perfectly attentive parent, he still has his moments. Shit still hits the fan. Thus I try not to get all uppity about kids behaving badly.

Last week, however, I couldn’t help but dread what lies ahead for my huggable, fun-loving, free-spirited almost-two-year-old.

I understand there’s not much malicious intent in a three-old clocking a two-year-old in the face over a toy. But eight-year-olds bullying toddlers? Is this normal aggressive boy behavior? Am I that naive? Do third graders routinely pick on two-year-olds? Or were these kids just bad seeds?

I began to picture Henry in the third grade, making enemies on the playground, confused about his place in the social strata of the school yard, resorting to cruelty to secure his place among the elite. I pictured him calling a kindergartener a baby for no reason other than to inflate his own eight-year-old ego, to make himself appear cooler in the eyes of his peers. I pictured him turning green, morphing into a child version of the Hulk, swatting and growling at his cowering schoolmates. I pictured him swatting and growling at me.

They tell me kids grow up fast, that tweens are highly insecure and teenagers are angry, but I like to believe that every generation has said this about the next generation, that somehow my child will be spared, that my protective bubble will follow him around like an invisible shield of armor, giving him the confidence to grow into a kind, loving, genuine adult without any awkward angry phases in between.

I know this won’t happen. There will be periods of malcontent, as there are period of malcontent for all people. Of all ages.

Still, I trust he’ll come out OK. Here’s what gives me hope: Last week we had an encounter with a young man working behind the customer service desk at a grocery store. After finding a toy helicopter in our cart, I delivered it to the front desk in case its owner came looking for it.

Henry was devastated.

“It’s not your toy, sweetheart. It belongs to another kid. We can’t keep it.”

(This was especially traumatic since he played with the toy for 45 minutes while I grocery shopped.)

“Ell-i-cop-der! Ell-i-cop-der!” He cried.

I wanted to let him keep it, but at the same time I’m a sucker for turning in lost articles because many times I’ve lost articles that were returned by strangers.

So I turned in the helicopter. The guy who took it looked at me strangely. He was about 17, maybe 18 years old.

“You know how kids are,” I said. “They get attached to toys. Someone might call to see if it was returned.”

“Uh, thanks,” said the clerk, placing it under his register.

Henry wailed. My heart broke. I explained to him that it was the right thing to do, a morality lesson that was utterly lost on a not-quite-two-year-old.

“Elli-cop-der! Elli-cop-der!” He cried.

I steered the cart quickly out of the store hoping to end this charade by swiftly placing Henry in his car seat, where I could refocus his attention by playing loud music.

My mission was cut short in the parking lot, when the clerk, out of breath, tapped me on the shoulder.

“M’am. Uh, I can’t stand to hear him cry,” he said, handing the helicopter to Henry. “It’s just gonna sit in a box behind the counter. No one will ever come for it.”

Henry took the toy, tears streaking his face.

“Elli-cop-der,” he said.

I took a long, grateful look at this kid, who one day might be a father. I wondered if he had young siblings at home. To go out of his way to give Henry this toy seemed at that moment … almost heroic. I wanted to hug him, to thank his parents.

“Thank you,” I said. “That was really sweet of you. He loves helicopters.”

We parted ways. I leaned in to kiss Henry’s wet cheeks.

“Grow up to be like that boy,” I said. “He was nice.”