From butt-lifting boxers to “frontal-enhancement” briefs that pack an extra inch onto the male unit, Andrew Christian has been making guys proud of their packages for over a decade. Lately, the L.A.-based designer who launched his first collection in 1997 has had plenty of his own reasons to be proud. Nicknamed “The Panty-Christ,” Christian ventured outside of underwear to debut menswear line Black by Andrew Christian last fall and has a women’s line in the works. He’s also a participant in BRAVO’s The Fashion Show, where he won first place during week three (you can purchase his winning design – a short raincoat that expands into a full-length trench – on the television show’s official site).

Christian will be in San Francisco tomorrow to meet fans and customers at Injeanious Lounge. On Sunday night, he presents his collection in a fashion show at Trigger. We caught up with Christian this week to chat about bubble butts, muffin-tops and that girl Daniella, who tried to sabotage him during last week’s episode of “The Fashion Show.”

Your Flashback briefs and boxers that lift and contour are known for turning regular guys’ bums into “the perfect bubble butt.” Let’s talk about bubble butts. What’s the allure?

Butts are popular. With the whole J.Lo movement, there’s been like more of an emphasis on the rear end than there used to be in the past. Obviously, that’s good for people who have it, but not everyone does.

What my underwear does is it takes what you have and makes it look a little bit better. It’s really hard to make your butt bigger by exercise. I know by experience.

Tell us about this Anti-Muffin Top Elastic on many of your designs. It sounds like the miracle we’ve all been waiting for.

It’s really great because the elastic has an extreme amount of stretch in it. It sort of moves and molds with your body. A lot of times, elastic will leave little lines in your skin, and this doesn’t do that. The Anti-Muffin Top elastic is also really comfortable to wear.

How does it feel to have your winning design from week three of "The Fashion Show" sold on Bravo’s site?

It’s really amazing to win that challenge out of all the designers that were there and having it be produced and having it be judged by Norma Kamali, who is so iconic.

What was going through your mind when Daniella accused of stealing her design in front of the judges?

I was just like, get real girl. I mean, for one thing, how could you be a team leader and I stole your design? That just couldn’t happen. She’s just a sore loser because she wasn’t in the top two.

Do you have any favorite designers from show?

I really like James Paul because he has his own aesthetic, and I think Angel is very inventive and creative with her design.

Is it hard to watch the show and know the outcome, but not be able to tell anyone about it?

It’s not difficult, but I think, for me it’s not as entertaining as it is for other people. I already know what the punch line is or what the outcome is going to be.

We hear your Black by Andrew Christian menswear line totally sold out after launching last fall. What’s next for Andrew Christian?

I am bringing back my Black line for fall and holiday. This time, the Black line is going to consist of a lot of the pieces I wore on "The Fashion Show." 

Any favorite spots in San Francisco?

Tangerine. 

Tell us about your Saturday appearance at Injeanious.

There’s going to be models, and I’ll be signing head shots. It’s really a chance for the customer to come out and meet me. And people need underwear advice.

How do you give someone advice on underwear?

I look at their body type and feel out what their personality is like. It’s just such a personal thing. It varies from person to person, and some people like have no allegiance to briefs or boxers and will wear whatever.

What’s your favorite Andrew Christian style to wear right now?

Right now, I guess my personal favorite is the Almost Naked Brief. It’s extremely comfortable because it’s made out of a bamboo fiber, so it’s eco-friendly. But I like it because it’s so soft.

Meet Andrew Christian in person on Saturday from 2 p.m. to 4 p.m. at Injeanious Lounge, 538 Castro St., 415-861-3963. On Sunday night, an Andrew Christian fashion show will take place at 10 p.m. at Trigger, 2338 Market St., 415-551-CLUB.