Wendy Williams tucked in her chest. Tomboy Kendra Wilkinson played the lady. Kirstie Alley got cheers in a ballgown. And supermodel Petra Nemcova channeled Christie Brinkley's "Uptown Girl" in a red hot way.

"Dancing with the Stars" costume designer Randall Christensen went retro for second night of season 12 competition, interpreting icons such as Ginger Rogers, Veronica Lake, and Donna Reed.

He takes us behind-the-seams to dish on some of the most talked about ballroom looks of the night:

Kendra Wilkinson Kirstie Alley  Ralph Macchio dwts costumes

Kendra Wilkinson, Kirstie Alley and Ralph Macchio. Adam Taylor, ABC

Kirstie Alley: Just two weeks into the competition, Christensen says he's already altering dresses to make them smaller for the former "Fat Actress" star who has pledged to shed 40 pounds dancing. Such was the case with the sublime ballgown he designed in a peachy shade of Alley's choosing. "Kirstie is a wonderful example of how hard work and dedication will pay off with a more sleek body," he says. "Dancing just makes the body more toned, which forces the costumes to be taken in and in and in!"

Kendra Wilkinson: Christensen let Ginger Rogers inspire Wilkinson's royal blue and fuchsia ballgown with elbow length hand-dyed gloves. Despite the Playmate's fears of not seeming lady-like, "I actually think Kendra channeled some of that Old Hollywood glamor," Christensen says. "Because of that she had a wonderful payoff this week."

Ralph Macchio: Christensen's team sewed more than 10,000 hematite crystals on the former "Karate Kid's" bedazzzled jacket.

Petra Nemcova Wendy Williams and Kym Johnson dwts costumes

Petra Nemcova, Wendy Williams and Kym Johnson. Adam Taylor, ABC

Petra Nemcova: The model, once again, played an active role in designing the red and yellow vintage-inspired dress and wide-brimmed hat that was a nod to Brinkley's turn in ex-husband Billy Joel's "Uptown Girl" music video. Nemcova ripped the dress skirt off mid-jive to reveal her model frame. "We had to have a hot and sexy skirt for the reveal and what's hotter than a red mini-skirt with tons of beaded fringe?"

Wendy Williams: The talk-show diva made it clear she wanted to keep her surgically-enhanced girls from taking over the dance floor. (Perhaps it had something to do with judge Len Goodman's comments about her "dumplings" during the season premiere.) Christensen accommodated with a Donna Reed-inspired rhinestone-bedazzled bright pink "house" dress with modest lines. "Wendy is experiencing the very same feelings and concerns that every competitor has, especially this early in the competition," Christensen explains. "She wants to feel confident and in control and most of all glamorous and sexy." And yes, she really danced "Spanx-free."

Hines Ward: The Pittsburgh Steelers wide receiver scored big with the judges in a classic tuxedo with a twist. Christensen stitched it in black velvet to coordinate with partner Kym Johnson's sublime Veronica Lake-inspired dress, and tucked red satin into the suit lining hoping it would pop on the dance floor. It did as "Hines really flew!"

Chelsea Kane. Adam Taylor, ABC

Chelsea Kane: The Disney star's deliberately wacky jive costume, which included a fitted corset, rosette, floral organza trim, hematite baubles, polka-dot briefs, tattered tulle, silver-leather strips and striped knee-highs provided Christensen with his shopping entertainment for the week. "Chelsea is very adventurous and great fun to work with."

For more ballroom fashion details, read last week's costume recap.