At home in Jenkintown, Sean Jimenez had a decent job, a woman who loved him, and two young sons who bore a striking resemblance to Dennis the Menace, just as he did when he was little.

But Monday night on a Kensington sidewalk, Jimenez had nothing but the clothes on his back, a few dollars in his pocket, a cellphone, and a drug addiction that apparently took his life. He was pronounced dead there at 11:10 p.m.

The ODs may have resulted from heroin cut with a synthetic opioid like fentanyl or from purer heroin than the users were accustomed to, authorities said.

On Tuesday night, Jimenez's best friend, William McMonigle, who had known him since they were boys on a Manayunk playground, sat down with Jimenez's sons, ages 6 and 12, and told them their father was dead.

"It was important for me to hug his kids and whisper to them, 'I'll always be there for you,' " said McMonigle, 45.

The 6-year-old knows only that his daddy is in heaven, but the 12-year-old understands how it happened. So McMonigle took the older boy aside and shared that his own father had died of a heroin overdose 22 years ago.

"I had to tell his 12-year-old my story, so he didn't think he was alone," McMonigle said.

Now McMonigle and longtime girlfriend Amy Zaccario - who lost her father to a heroin OD in 2006 - are planning Jimenez's funeral, the Havertown couple said Thursday.

"Here's two people who vowed never to touch heroin, but here heroin is touching us," McMonigle said.

Zaccario, who attended Roxborough High School with Jimenez and met McMonigle through him, also lamented that she and her boyfriend keep losing loved ones to the drug.

"It's destroying us," she said. "We argue with people we know. We fight with them. We tell them our story. But nothing makes a difference."

'We were inseparable'

Adopted as a child, Jimenez grew up in Manayunk, where he would hang out with McMonigle and about 40 other boys at Wissahickon Neighbors Park.

"We did everything together. We were inseparable," McMonigle said. "We were like Tom and Jerry, or Batman and Robin."

After graduating from Roxborough High, Jimenez started a career in furniture sales, which he loved, McMonigle said.

Smart, headstrong, and argumentative, Jimenez was a "Mr. Know-It-All" who read the Daily News religiously and would take on anyone in an argument about the Eagles, the couple said.

A few years ago, Jimenez was prescribed pain pills after an accident, but when the prescription ran out, he resorted to buying $5 bags of heroin about four times a week to ease the withdrawal, McMonigle said. He always snorted the drug instead of injecting it, his friend said.

"He never shot it ever in his life. He hated people who shot it," McMonigle said. "He used to think he was better than them. I told him, 'You aren't.' "

Despite his addiction, Jimenez kept a job, his girlfriend, and their two kids.

"He was an absolute functioning addict," McMonigle said. "He worked, he came home, he gave his check to his girl, and got a bagger for $5."

Last year, Jimenez and his girlfriend moved their family to Jenkintown to get their children into a better school district.

He lost his job, then went door to door seeking work. About three months ago, a Jenkintown tavern hired him as a cook, McMonigle said.

'A bad bag'

Shortly before his death, Jimenez told McMonigle that his dealer in Kensington had said the elephant tranquilizer carfentanil was being mixed with heroin in Philadelphia.

But Jimenez wasn't worried. He believed that dealers never cut $5 bags with other drugs.

"He thought his dealer would never do him wrong," Zaccario said. "They all go down there thinking their dealer isn't going to give them a bad bag."

No ID was found on Jimenez, McMonigle said, so the Medical Examiner's Office left messages on Tuesday for people saved in his cellphone, which is how his girlfriend and friends found out.

"I said, 'How . . . do you know it's him? How do you know that somebody didn't steal his phone?' " he said. "They asked me if I'd be able to identify an orange 'Homies' hat. I bought that hat for him two weeks ago, so I knew it was him."

Jimenez's adoptive mother died last year, so McMonigle and Zaccario have taken on the cost and planning of the funeral. A GoFundMe account they set up to help pay for it had reached $975 toward its $3,000 goal by Thursday evening.

After the funeral, McMonigle said, several friends will return to the Manayunk playground.

"We're going to play a Wiffle ball game and we're going to fill the ball with his ashes and blast him off," McMonigle said.

If you had a loved one among the 35 fatal overdose victims between Dec. 1 and Monday and you wish to contact staff writer Stephanie Farr: farrs@phillynews.com

215-854-4225@FarFarrAway

Staff writer Don Sapatkin contributed to this article.