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."

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."

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.