The True Blood star – and PEOPLE's Hottest Bachelor – says that before the seventh and final season of the HBO vampire drama started filming, he sensed what awaited his werewolf alter ego, Alcide.
"I read the finale of last season and the first thought I had was, 'They're gonna kill Alcide,' " Manganiello, 37, tells PEOPLE.
Sadly, he was right: In one of the show's most shocking twists ever, the rugged, loyal werewolf met his end on Sunday night's episode.
Although it appeared at the start of the season that Alcide had finally found happiness with his trouble-prone dream girl Sookie, "she logically needs to settle up with [vampires] Bill and Eric in whatever form that takes," says Manganiello.
"And Alcide was in the way of that. You can't really have Sookie [Anna Paquin] break his heart because he's a good guy and he loves her. So the only thing left to do is kill him."
When producers took him out to dinner to break the news before filming began, Manganiello recalls, "I said, 'I know. You have to do this. I called it.' Then I ordered the biggest steak at the restaurant and that was it."
Still, filming Alcide's death scene proved trickier than the actor anticipated.
"It was about 30 degrees outside, and we filmed in the middle of the night." And because Alcide had just shifted from his wolf form to his human form, he was naked. (With abs like this, why not?)
During the death scene, "I had to lay on the ground for hours, naked except for my [strategically placed] sock," says Manganiello. "It was freezing cold. The director's like, 'Stop rattling!' And I'm like, 'I'm trying!' "
Although the star, who just made his directorial debut with the new documentary La Bare, says he will miss "playing such a big-hearted character – he's this essentially savage monster, with an incredible amount of vulnerability" – he is looking forward to his next projects, including the Magic Mike sequel, shooting this fall.
Still, he didn't leave Bon Temps without taking at least one souvenir.
"When I got up off of that ground in 30 degrees after playing the death scene, I brought the sock home with me," Manganiello says with a laugh. "I'm gonna frame it up and put it in my guest bathroom."