Christian Siriano is on fire. Michelle Obama wore one of his dresses during her speech at the Democratic National Convention; the designer launched a bridal and plus-size collection earlier this year, and the 30- year-old just presented a spring show of chic cocktail dresses and stunning, colorful gowns to rave reviews.

But the big talker this season: his diverse model line-up. In a Fashion Week that kicked off with a scathing op-ed in the Washington Post by another “Project Runway” alum, Tim Gunn criticizing the industry on it’s lack of options for average size women, it was both refreshing and reassuring to see a designer step up. Not only did Siriano cast models of various sizes, but he featured an ethnically diverse lineup, as well. We caught up with Siriano right after his show.

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Why did you decide to include plus-size models in this season?

It was all about diversity this year. We wanted different ethnicities and women of all shapes and sizes. I just think that’s what’s happening right now in the world. There’s a lot of hate going on. So it isn’t about having plus-size women, it’s about celebrating everyone. Fashion is fun and it should be that way.

We loved the glam gowns, tell us about them.

We looked at a lot of vintage photos from the ’60s and ’70s of Jackie O in Capri on holiday. I was trying to give my customer that perfect holiday — and pack her bags for her.

When did you find out Michelle Obama was going to wear your dress to the DNC?

I was on my sofa watching. At first I didn’t even know it was mine, because I was nervous. I was like ‘that’s probably not it, but it looks really similar.’