He has put his name to a number of magic set for retail sale and has worked closely with producer Paul Andrews in creating magic for his television and live shows. Mulhern does not work with a regular assistant for his illusion performances, preferring to work with a range of guest celebrity assistants. Most notable of these is his former Saturday Showdown Co-host Holly Willoughby, who has assisted him on many occasions in a variety of illusions including being sawed in half. Other celebrity assistants have included the singers Katherine Jenkins, Rachel Stevens and Louise Redknapp, and the actress Mischa Barton. 

Stephen Mulhern is now single and has never gotten married. The last recorded relationship was with Emma Barton who was his girlfriend and they were dating since 2008. He is famous for the Ministry of the Mayhem and the zodiac sign is Aries. Some people even say that he is homosexual. He says that he had been in many relationships and these relationships did not last for long. "There’s only one woman in my life and that’s Emma Willis! She’s so nice. There’s no nonsense ­ you want any advice, she’ll bring it. I was at her husband Matt’s McBusted concert with her recently and she said: ‘By the way, if the camera comes on us, we’ve got to kiss.’ She swears she never set this up, but the camera did come on us and we went for it ­ when you see the pictures, it’s really funny. She still says she had nothing to do with it ­ but I doubt it" His net worth is 3 million and his height is 6 feet with one inch. He works under Prime Performers Booking agent. 

In January 2018 Mulhern will also be presenting The Big Soap Quiz: Coronation Street Vs Emmerdale.