Brion Whitley — who says he’s “The Most Hated Man on Netflix” – tells TMZ he regrets the threesome he had on “Temptation Island” … and, the negative backlash it’s brought on him and his girlfriend.

We spoke with Whitley … and, he tells us his threesome with Alex and Courtney on the first season of the hit Netflix show was a mistake — but, he’s learned lots of lessons from it.

ICYMI … Brion is receiving major backlash after the cameras caught him having a steamy threesome with two of the 12 tempters on the island — and, many on social media are blasting him for being unfaithful to his girlfriend, Shanté.

Of course, Brion regrets everything that’s gone down … but, he says he and Shanté have never been better — adding he “hates the way I had to learn, but I do like the fact that I did learn.”

Whitley says he’s slowly building back trust with his better half … telling us the two are living together — and, he’s fully committed to honesty and transparency moving forward. All of this, we’re told, is in service of becoming a better partner and possibly future father.

While most of their days are pretty routine — filled with cooking shows and antique store visits — Brion does admit the social media backlash is far from the everyday trolling. Not only have Brion and Shanté had to limit comments on social media, but they’ve also received numerous death threats from outraged fans.

Whitley says he can handle the hate as long as Shanté — who is crushing it as a Pilates instructor-trainee in Georgia — and her family aren’t in the line of fire … but, clearly people aren’t laying off her either.

Brion adds the editing on the 10-episode show certainly doesn’t help the public’s opinion of him … but, admits he gave producers all the content to work with — and, he’s owning that.