Dex Magnum (AKA Dax Magnum) has been working in the porn business since around 2006. He does much of his work behind the scenes, working as a lighting technician on flicks like Cum Coat My Throat. Dex has too much screen presence to stay out of the spotlight, though, so he's made a number of appearances in hardcore porn films over the years.
One of Dex's most popular films was the parody Celebrity Apprentass. Like the other flicks he appears in, Dex isn't actually getting his dick wet, but his role as Donald Hump Jr. helps drive the action and keep things moving along. The show it's based on is all about Donald Trump abusing minor celebrities, deciding who gets to stay and who gets fired. As you've probably guessed, this film is similar in nature, except the celebrities are pornstars, like Brooke Belle, getting judged on things like how well they take facials.
He also appeared briefly in Celebrity Pornhab With Dr. Screw, appearing alongside sluts like Penny Flame. The dude's been rubbing elbows with some of the hottest names in the business, and he obviously loves his job. Dex Magnum is just a minor celebrity in the world of pornography, but he has contributed to some of the greatest films of our era.