Law officers stand on a street during protests in Baton Rouge. (Shannon Stapleton/Reuters)

It felt wrong to host a party over the weekend.

There had been lives lost in Baton Rouge, Falcon Heights, Minn., and Dallas. There had been videos of black men dying at the hands of white officers, and white officers dying at the hands of an angry, delusional black veteran. There had been tense protests with police in riot gear. There had been blood, tears and so much hatred.

But I had a boy turning 12 and a birthday party to throw for him. Buying water balloons and frosting a cake never felt so joyless.

Parents dropped their kids off, and we all had the same look in our eyes, a tiny head shake, a hug tighter than usual.

One of the moms sat down in my kitchen, maybe not quite ready to leave her boy for 24 hours. And she began to cry. Her husband is a black D.C. police officer. Her son is a black boy.

Demonstrators sit on the steps of the Louisiana capitol building in Baton Rouge. (Shannon Stapleton/Reuters)

“I’ve never been so scared for him,” she said.

“Which one?” I asked.

Truth is: both.

They have already gone over it, again and again, how their son should behave if he is approached by police. Be respectful. Do everything they say. Never wear your hoodie up. Wear a cap if it’s cold.

It’s what black parents have long told their children. They did not need any reminders from former New York City mayor Rudy Giuliani, who said Sunday that African Americans must teach their children to respect law enforcement. As if that’s the solution to police brutality.

There’s a parenting checklist in the black community that rarely crosses the minds of white parents. And there’s a police-wife checklist that rarely crosses the mind of civilian spouses. Goodbye. Be safe. Kiss. Will you make it back home?

My friend’s husband has never been shot at, and he has never shot at anyone — typical of many police careers. He is a veteran who does not patrol anymore. He works downtown, at police headquarters.

“But it’s the first time I’m really scared for him, after all these years,” she said.

It’s a feeling I can only imagine.

Policing is not the most dangerous job in America. A higher percentage — and in many cases, a larger number — of loggers, construction workers, truck drivers, taxi drivers, steel workers and roofers are killed at work, according to the Bureau of Labor Statistics.

But the rage-fueled attack in Dallas that killed five officers and wounded seven others reminds her that he works in a country with, statistically, more guns than people. And even the funny story she told about the guy who tried to bring a python into police headquarters the other day could not relieve the sense of threat.

Eventually, she left her son at the birthday party and went to have a quiet dinner with her husband.

We took the boys on a short road trip, splashed around in a river for most of the day, and then headed back home for dinner and a sleepover.

On the way, we stopped for snacks and a bathroom break. We pulled over in Loudoun County, one of the nation’s wealthiest jurisdictions, at a convenience store swank enough to carry designer turkey jerky. I had the boys pick out some snacks for the rest of the drive before they headed to the restroom.

The five tweens — two white and three black — were a little loud, but not rude, disruptive or suspicious.

My son used the bathroom, went back into the car, and then one of the other boys went into the stall.

The three black kids remained, waiting in line outside the restroom door. I was checking out the cherry chipotle turkey jerky when the clerk left his cash register and ran over to them.

“Why are you standing here?” he demanded.

I raced over, laden with snacks, and explained to him that they were with me and waiting to use the bathroom, just like their two white friends had.

“Oh, sorry, ma’am. I’m sorry,” he backed away.

So there it was.

The clerk did not see the three 12-year-olds as I know them: the sweet-faced, fastidious boy who wears a suit and tie to every science night, his classmate who plays trumpet like an angel, the wisecracker who also does mental math so fast it’s scary. They are the sons of two lawyers and a police officer.

Like the people who took part in a 2014 study, “The Essence of Innocence: Consequences of Dehumanizing Black Children,” published in the Journal of Personality and Social Psychology, that clerk saw African American kids as less innocent than white kids.

I burned white-hot inside at the way that clerk profiled and harassed three of my son’s friends.

What if this was the way the world saw my own children every day?

We ended our busy weekend with dinner at the home of friends, a white pastor and his wife who have adopted two black children. While the kids played soccer in the back yard, we talked about hope vs. hopelessness.

It’s too easy to look at our country and the huge strides we have made — from a two-term black president to the multiracial group of kids having a water balloon fight during a birthday party — and believe we are post-racial.

But what happened in Louisiana, Minnesota and Texas is a reminder of how far we have to go. And I have not even touched on the huge racial disparities in incarceration rates, income and employment. What we are experiencing now — the inequality alongside centuries of racial hatred — is simply unsustainable.

We desperately need more effective police training, criminal-justice reform, and better schools and job-training programs. But we also need to open our hearts, to stop pretending that progress means racism has gone away and acknowledge that we still have a lot to overcome.

Or as the pastor we had dinner with put it: “The change? It can happen individually.”

Changing what’s in our hearts is something every American can do right now. And it’s something every American must do if we ever hope to move our country forward.

Twitter: @petulad