Jennifer Lopez's InStyle Cover

Jennifer Lopez wears a Jil Sander dress, Hermes cuffs and her own ring for InStyle cover. Photo: Michelangelo Di Battista for InStyle.

Jennifer Lopez is showing everyone what 40 and fabulous looks like in the September issue of InStyle.

The dancer/singer/actress/designer/mom graces the magazine's 15th Anniversary Issue's cover in a cutting-edge, sculpted Jil Sander dress and Hermes spiked cuffs, all in a sophisticated black and white palette (minus her bright cherry red lips).

Inside, the black-and-white theme continues as the mother of two smolders in classic JLo style -- thigh-high Christian Louboutin leather boots paired with a puffy-sleeve Louis Vuitton dress and Marc Jacobs bracelets, and later in a body-hugging hooded sweater by ALC, the label of Lopez' ace stylist Andrea Lieberman.

As seen in the shoot's exclusive behind-the-scenes video (check it out here), despite a short hiatus after having twins, Lopez still knows how to pose like a pro, working it in floor length gowns by Versace Atelier, Givenchy, and Nina Ricci, as well as a Herve Leger cut-out dress that proves Lopez isn't packing an ounce of baby weight.

"She knows how to play for the camera," says photographer Michelangelo Di Battista of Lopez. "It makes my job easy."

Jennifer Lopez in Louis Vuitton dress and Christian Louboutin heels

Lopez has all the right moves in a Louis Vuitton dress, Christian Louboutin thigh-high leather boots, Marc Jacobs metal and glass bracelet and her own ring. Photo: Michelangelo Di Battista for InStyle

Aside from discussing her upcoming projects -- a new fragrance, romantic comedy and album -- Lopez opens up to InStyle about her marriage to Marc Anthony: "This is my third time. I don't even think I tried in my other marriages, which was immature and not knowing better. It's been a lot of hard experiences and a lot of ups and downs and a lot of mistakes. I'm old enough to know now that relationships take work."

Lopez on her chameleon-like style: "I still slip into different styles very easily. I can be a little bit hip-hop in sweatpants and sneakers and a baseball hat. Or I can put on a head wrap and get kind of bohemian with glasses and a caftan. I can dress conservative '60s glamour, or I can go supermodern chic... I love all different kinds of things. I'm open. I think that's what makes it exciting to people. They don't know what I'm going to do next. Honestly, I don't know half the time."

Jennifer Lopez in striped ALC sweater and Hermes cuff

Lopez in an ALC cashmere sweater from her stylist Andrea Lieberman's line, Hermès and Pat Areias cuffs and her own ring. Photo: Michelangelo Di Battista for InStyle

To read more of Lopez' interview -- where she discusses motherhood, playing muse to her husband and why Barbra Streisand is her idol -- head over to InStyle.com.