She's ready for summer! Singer Ashlee Simpson opened up to Us Weekly Tuesday, June 10, about her big sister Jessica Simpson's much-anticipated summertime nuptials to Eric Johnson at the E3 Convention in L.A.

"I don't know when it is!" she demurred of Jessica's wedding date with a laugh. (As Us Weekly revealed last month, the fashion mogul will tie the knot over Independence Day weekend.) "I'm really excited about it," said Ashlee of her sister's second trek down the aisle. Ashlee, who got engaged herself to Evan Ross in January, went on to gush about the bride-to-be's "amazing taste" and dished on her bridesmaid's dress for the big day.

"My dress is really beautiful!" she said. "It's really, really stunning." Us revealed that the bride-to-be will not be wearing white. "Jessica is having something unique made," a source told Us. "It will be very different from the Vera Wang she wore to wed Nick Lachey."

"I've always borrowed her clothes," Ashlee added. "It's fun to go into her wardrobe and do something different because I'm half-tomboy, half-bohemian. It's fun to have her dress me up... I was either a doll for her growing up, or the one who messed her shoes up!" Ashlee has previously modeled for her sister's empire, and collaborated on the brand's tween line.

Updating Us on her 5-year-old son Bronx (whom she shares with ex-husband Pete Wentz), Simpson said: "He loves when Jessica is over!" Her son also likes to play with her fiancé Ross, Diana Ross' actor son who will star in Mockingjay Parts 1 and 2 in the Hunger Games franchise.

"Bronx loves to boss everyone around on video games," she said of her son's love for Skylanders. "He's just amazing at it. He's really smart and loves it, so of course Evan and I love to play with him."

Summertime plans with the little one, said the proud mom, will include swimming, playing video games, and jumping on the trampoline.

Source: US Weekly