A source tells Usmagazine.com that early Thursday morning, he hit the Portofino Sun Tanning salon on Manhattan's Upper West Side.
He arrived in a black suburban with an entourage.
Johnston, 19, told Usmagazine.com Wednesday night that the shoot will take place "in a couple locations. I honestly don't know where any of them are." But he added all photos will be taken "inside."
What can we expect?
"You'll have to wait. I know what I'm going to do, but y'all don't," he told Us at the 2009 Fleshbot Awards in NYC.
After two months of working out (three hours a day, six days a week), he told Us he plans to celebrate after it's all done with some junk food.
"I'm not looking forward to eating a salad or grilled chicken for a long time after tomorrow – or fish," he told Us on Wednesday.
"Shoot, I don't know, I'll probably go to Taco Bell and eat the nastiest thing on the menu!"
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