Adam DeVine

The guys from "Workaholics" better give a big thank you to co-star Adam DeVine ... 'cause a porn site is offering to let them watch a smut session IN PERSON -- for giving it public props. DeVine told Rolling Stone last week he has trouble writing at home because of Porn Hub ... adding, "they know…

29-year-old Blake Anderson (left), 28-year-old Adam DeVine (center) and 32-year-old Anders Holm (right) put on their best 'Workaholics' costumes and posed for pics at San Diego's International Comic-Con. The question is...