EXCLUSIVE: Jennifer Aniston Still Mourning 'One Who Got Away' As She Recovers From PTSD-Inducing Stalker Scare

Permanently single Jennifer Aniston is still lamenting a man who got away nearly 30 years ago as the Friends beauty lives with the emotional aftermath of two divorces, multiple failed romances and her recent stalker terror.

In 1990 – before Aniston became a household name on the NBC hit – she began dating fellow struggling actor Daniel McDonald, who was nine years her senior, RadarOnline.com can reveal.

"Jen was born in Los Angeles and raised in New York City, but her parents were strict," a friend told us. "And when she moved back to L.A. and met an older man, he was protective and she felt safe."

"Jen and Dan dated for almost five years before she landed the role of Rachel Green on Friends. And while Dan was happy for her success, they'd talked about moving back to New York – something Dan wanted because his goal was to perform on Broadway," a source told us about the ex she pines for.

They added: "He considered himself more of a New York theater guy, and he and Jen had pretty much made a pact to go back."

According to our source, Aniston, now 56, was faced with a hard decision: move back to New York with the man she loved or stay in California for the sake of her career.

"She knew Friends was the chance of a lifetime and she had to stay, while Dan pursued his dream on Broadway," the insider added – also confiding: "Jen and Dan kept in touch – but with time, they drifted apart."

Aniston found sitcom fame and was married twice – to Fight Club hunk Brad Pitt from 2000 to 2005 and Leftovers actor Justin Theroux from 2015 to 2018.

Meanwhile, McDonald earned a Tony Award nomination for 1997's Steel Pier, got hitched to filmmaker Mujah Maraini-Melehi two years later and had two children.

Tragically, he was diagnosed with terminal brain cancer in 2006 – and our source said Aniston was devastated when he passed the following year at age 46.