Project Runway reality star details heartbreaking reason he hasn't had sex in 43 years

Project Runway star Tim Gunn has shared the heartbreaking reason behind his decision to remain single and celibate for over four decades.

The fashion consultant opened up about his love life and how he's learned to love living alone following a tough heartbreak.

Gunn, 72, who was a mentor on Project Runway until 2017, recalled how breaking up with an ex-boyfriend at the age of 29 drove him to abstain from sex and romantic relationships.

He has now been celibate for 43 years and admitted he 'wouldn't have it any other way'.

Tim Gunn has been celibate for over four decades (Nathan Congleton/NBC via Getty Images)

"I had a very serious nine-year relationship in Washington, D.C., and I loved this person deeply and would have done anything for him. I still remember the night that it all ended," he said on the Dear Chelsea podcast, hosted by Chelsea Handler.

Gunn explained his then-boyfriend simply asked him to leave as he no longer had 'patience' for him and the pair separated. Despite the fact Gunn had been living with his then-boyfriend 'for years', he still had his own apartment thankfully and left.

The reality TV star revealed that his ex then informed him he'd been sleeping with 'just about everything that walked by' while he'd remained loyal, and as the break-up occurred during the height of the AIDS crisis, Gunn was left concerned.

"The self-pity then turned to completely unbridled anger because I thought he may have given me a death sentence," he added.

"I was tested every six months for ten years for HIV, and thankfully, I had a clean slate."

Adding to his heartbreak, his ex was also his co-worker at the time, meaning they still had to see one another after deciding to part ways.

The break-up impacted Gunn's attempts to engage in new romantic relationships and he admitted that each time he'd been tempted to see someone new, he'd be reminded of his heartache and it would 'just take the desire away'.

Tim with Project Runway co-star Heidi Klum (Mark Sagliocco/Getty Images)

Despite the pain, Gunn has no regrets. He admitted it was 'a bit of an adjustment' when he began living alone and being celibate, but has grown to love his lifestyle.

It's not the first time the Ugly Betty star has spoken about his love life. He previously described himself as 'kind of asexual' when discussing his past.

He told People in 2010. "I've always been kind of asexual. That breakup was a cold shower to last a lifetime. When people hear I haven't had a boyfriend since 1982, they often whisper, 'Does he not have sex?' That's right!"