Stylelist has an exclusive interview with celebrity designer Heather Thomson, creator of the popular -- and comfortable and effective -- Yummie Tummie shapewear top. She's also the former creative director for Beyoncé's House of Deréon, and designer for Diddy's award-winning Sean Jean menswear line. Heather's accomplishments also include helping Jennifer Lopez create the Sweetface line.

Heather dished with StyleList about her time working with celebrity designers, as well as her latest creation, the RIPT Fusion– pronounced "Rip Tee" – a line of compression shirts for men who want fashionable core support. And she even gave us a sneak peak at the Yummie Tummie Fall collection, which includes some of the sexiest shapewear we've ever seen!

Sexy Stars Who Love Yummie Tummie

    Sexy New Yummie Tummie Teddy
    It's the sexiest shapewear we've ever seen! It holds you in and up!

    Yummie Tummie

    Heather Thomson on the set with Beyonce and Solange
    Heather worked with talented Knowles family on the Dereon, House of Dereon and Miss Tina brands.

    Heather Thomson

    Destiny's Child Blesses Heather's Unborn Child
    Heather, while pregnant with her second child, Ella, flanked by Michelle Williams (on her left) Kelly Rowland and Beyonce Knowles. Heather created the first Yummie Tummie for herself, after the birth of her first child, Jax.

    Heather Thomson

    Tina, Matthew and Beyonce Knowles
    Heather confirmed that Beyonce really is as nice in person as she seems, and gives credit to Matthew and Tina Knowles for raising such grounded daughters.

    Heather Thomson

    Damon Dash, Diddy and Heather Thomson
    Heather honed her menswear design chops while working with Diddy at his award-winning Sean John line.

    Heather Thomson

    Jennifer Lopez and Heather Thomson
    JLo and Heather -- just two cool chicks into fun and fashion!

    Heather Thomson

    The RIPT Fusion
    Superman abs -- or the appearance of them -- can be his, with the RIPT Fusion "men's undershirt on steroids!"

    RIPT Fusion

    Yummie Tummie Briefie
    New in the fall collection: Yummie Tummie comfort and control in a sexy bottom.

    Yummie Tummie

    Yummie Tummie Lace Print Strappy
    The comfortable and sexy Yummie Tummie Strappy, now in a trendy lace print. So cute no one will even realize it's shapewear!

    Yummie Tummie

We love our Yummie Tummies! Tell us about the new collection:
Since we launched a little more than a year ago, we've been building on the basics from the first collection. In the spring we added some great hot weather looks, including the Bare Back, a halter style. Our fall collection will add even more versatility – and sex appeal!

Before you started Yummie Tummie, you were a designer for some big name celebrity collections.
That's right! Most recently I worked for the beautiful and talented Beyoncé and Tina Knowles. I was their creative director, helping them launch and build the brands of House of Deréon, Deréon, and Miss Tina, an exclusive collection we did for HSN.

What was it like working with Beyoncé?
When I started it was a brand new company, and it was wonderful to work with such a talented and creative mother-daughter team. Tina had a talented mom who taught her to sew, and gave her those great creative genes. And then Tina passed that talent to her daughter. Beyoncé also paints, she can draw and and she really knows what looks good and fits well.

Beyoncé is always so gracious in interviews. Is she really that nice?
Beyoncé is a shining star. Matthew and Tina Knowles gave her a strong upbringing with great values. She's so beautiful and she's normal -- people can relate to her and look up to her. She understands that the talent brings responsibility, that the kids look to her example. You know, she always takes the time to greet every single person in the room, every time, even though she's always so busy.

Earlier in your career you worked with Diddy, right?
Yes, I helped launch Sean Jean in 1998 and it was an amazing ride with him to the top of men's fashion world. Sean John was nominated for awards by CFDA immediately for three consecutive years, and then won menswear designer of the year in 2004. This was really before celebrities had fashion lines, so it was pretty radical.

That must have been an exciting environment!
Well, the collection reflected Puffy, and his life wasn't boring! It was street fashion meets high fashion, and let me tell you, our shows were the hottest ticket in town! They were a fusion of clothes, music, and his big personality.

He definitely has a lot of personality!
I love him like a brother. We have a special relationship and a unique admiration for each other. He has an uncanny ability to wear stuff that most men can't wear, like a fur coat. And men traditionally don't wear white, especially optic white. Sean Jean was an inclusive line for all men of all race creeds and colors. It broke down barriers, and said "Let's look at men's fashion for what it is -- let's make it attainable."

And through Diddy you met Jennifer Lopez?
Yes, we became friendly while I was working for Puff, and when she first launched her line she'd say, "Hey, what do you think of this?" We were close enough for me to be honest and say that her earliest line didn't reflect her amazing, bubbly, girly-girl femininity.

How did that turn into working with her?
At that point I'd been with Puff for over four years, and I was itchy to do some women's fashion. I thought I could make a difference for her. In two years we launched the Sweetface label, and pulled the JLo brand together so that it reflected the essence of her style, which is what people were so drawn to.

Did you send her Yummie Tummies when she had the twins?
Oh, Max and Emme! I'm so happy for her, that she's been blessed with the family she wanted so very much. Yes, we sent her a big box of every style Yummie Tummies. Even someone as beautiful as Jennifer can appreciate a little support after having two babies!

What's next for Yummie Tummie?
Well, the RIPT Fusion just launched, which we call a "men's undershirt on steroids." There's been a great response to it – actually, there was a great demand, which is why we developed it! Men want the same kind of support and contouring that the Yummie Tummie gives to women. They've been wearing athletic compression shirts for core support for years. RIPT gives men a versatile, stylish choice for that same kind of support. You'll feel good wearing it with a suit, or to the gym.

Let's get back to the fall collection. How sexy is sexy?
Our new fall collection is full of hot, must- haves! We expanded our styles to include our sexy Yummie bottoms and Yummie tops by cup sizes, and added exclusive lace print and color blocked styles, all in our beautiful new color palette for fall.

What's your favorite new item?

I'm most excited about the new Yummie Tummie teddie. You know, there's nothing forgiving about a negligee, and that's when you should feel your best. So I created the Yummie Tummie teddie, a one piece design with our exclusive shaping mid-section, under wire lace cups and a snap-crotch, lace, boy short. Best of all, like all Yummie Tummie pieces, it's versatile! You can wear it on its own in a "private moment", feel sexy and sleek in it under a dress, use it to smooth and shape your body under a fitted jacket or to give you the security and confidence you deserve in your low rise jeans!

We can't wait! When can we get our hands on the fall collection?
The fall collection will be available at the end of June. We let our Yummie Tummie Facebook fans know all about the new styles when they come out, so becoming a fan is the best way to stay in the know!

We are big fans of Yummie Tummie, and thanks to our friendship with Heather, we also scored a sneak preview of the Yummie Tummie fall collection, along with some of her personal photos with Beyoncé, Diddy and Jennifer Lopez! Check them out in the gallery, and as Heather would say, "Stay yummie!"