At one point in his life, Roger Craig Smith knew nothing about wedding dresses. Now, after seven years doing voiceover narration for TLC’s “Say Yes to the Dress”? Just test him.

“A-line, ball gown, fit and flare,” Smith says triumphantly, rattling off various gown descriptors. He can also tell you all about crinoline and tulle, if you like.

Unlike you dudes who have to make up an excuse when someone walks in on you watching a “Say Yes to the Dress” marathon, when Smith’s girlfriend catches him in the act, he has a legitimate excuse. Since the incredibly popular wedding dress shopping series began in 2007, Smith has narrated every episode of the show (amounting to hundreds) and all of its spin-offs. “Say Yes to the Dress: Atlanta” wraps up its seventh season on Friday.

For the uninitiated, “Say Yes to the Dress” is based at Kleinfeld’s Bridal in New York. Each episode follows several brides as they come in searching for their perfect gown and the dress experts who help them. At the end of the half-hour, the women are asked: “Do you want to say yes to the dress?” Most of them do — hugs and tears all around. It’s simple, but it works. The original show consistently earns great ratings for TLC and is rolling into its 12th season this year.

Meanwhile, Smith’s role is the unseen voice guiding the show. His voice pops up to say things like “Jenny pulls a satin ballgown to get a sense of the bride’s style” and “Melissa’s sexy lace gown is an unexpected hit.” Though the narration seamlessly blends in to the point where you almost don’t even notice it’s happening, it’s an integral part of the show, as it amps up the drama and provides transitions between scenes.

What makes the whole thing even more surreal to Smith, 38, is that he’s also the voice behind many cartoons and video games, including “Resident Evil,” “Assassin’s Creed,” “Avengers Assemble” and more. The contrast makes for pretty entertaining days on the job. One minute, he’s in the studio narrating a show that wonders if a gown has too many crystals or if a bride should go with a diamond tiara; the next, he’s voicing video game characters that are trying not to get attacked by zombies.

“It’s been an interesting journey for me,” Smith laughs. But it’s actually great to have so much variety in the voiceover world. After all, he can have fans at gaming conventions and bridal shows. How many people can say that?

While he didn’t know much about “Say Yes to the Dress” going in, he’s found it a fascinating topic. Before he started, his thoughts about wedding gowns were essentially, “Aren’t they all just big poofy white dresses?” However, through his behind-the-scenes role, he’s learned a lot about the intensive process and everything that goes into picking the perfect dress. Not only is it a pricey investment, but it it can be a deeply personal decision.

“Truly at the heart of it is what this moment represents for women,” Smith says about why the show’s been such a success. The many emotional stories that come out of dress shopping often surprise him. “You’re celebrating what is arguably an occasion for one of life’s biggest moments.”

The strange part is that Smith doesn’t even see the scenes he’s narrating. When he receives the scripts, he works from his home studio in Southern California, and gets on the phone with a producer who gives him some context as he reads each line. For example, for a bride worried about pleasing her entourage of friends and family with a certain dress, a producer would give him more details about the situation before Smith says: “The avant-garde ball gown needs to get the thumbs up from the Greek chorus out in the salon.”

Even for something innocuous, it always helps hit the notes properly if he knows about the scene. Plus, when he’s reading a line about Grandma not being there, it helps to know if it’s simply because she can’t find parking or…something more depressing.

While Smith never expected “Say Yes to the Dress” to go on this long, he’s not surprised that people keep watching — it’s easy to get addicted to TLC’s frequent marathons, either for gawking or genuine interest. (Though some of Smith’s male friends say they’ve only caught a few minutes of the show while their wives watch, they seem to know quite a few details about dress designers.)

So with all of Smith’s knowledge, does that mean brides-to-be should be lining up to take this under-the-radar expert shopping for their wedding gowns?

“Oh, gosh, no,” Smith said. While he can reel off wedding dress facts with the best of them, that doesn’t mean his skills translate to real life. “The first thing I would say is run for the hills — you would wind up in a burlap sack.”