Kim Kardashian Flaunts Major Cleavage in Plunging Tuxedo Dress, Flashes Rare Smile—See the Sexy Pics!

Kanye West's wife doesn't smile "too often," she's said, "because it causes wrinkles"

Kim Kardashian brought the girls out yesterday—and we're not talking Kourtney, Khloé, Kendall or Kylie....

The Keeping Up With the Kardashians star put her ample assets on display Tuesday in a plunging tuxedo dress. She Instagrammed a picture of herself looking rather seductive in the sexy, curve-hugging ensemble, captioning it simply, "Today's vibes."

Kanye West's wife posted another snap of herself int he menswear-inspired frock, only this time, she was smiling! (Kim revealed on Instagram earlier this year that she does smile—and "even laugh on occasion"—just "Not too often though because it causes wrinkles.")

The mother of one has a lot to be happy about these days, though. Just yesterday, in fact, Kendall and Kylie Jenner were just added as characters to Kim's super-successful app game!

"I don't know if I expected it to do this well," she recently told AdWeek. "I'm really thankful that it has because I've put a lot of hard work into it and spent a lot of time on it. It's how I think of my show—someone can always relate. People always want to get their mind off of things and have something fun to do because their lives are so hectic. It's a fun game that you can really get addicted to and just lose yourself in for a couple of hours."

"I hope to have a bigger presence in the tech world," she added. "I love coming up with different app ideas, and I have a few more that are coming out. Once you get started and you have this creative bug of ideas that you want to get out, I feel like I've partnered with the right team, and now I have the creative outlet to make that happen. I'm happy that people are into it and perceiving it well. I just want to create more apps."

That said, Kim admitted she's "really choosy" about what projects she's willing to take on. A huge reason for that? She wants to spend time with her and Kanye's 20-month-old daughter North West!

Kim's also hoping to expand her family in the near future. She told iTV's Lorraine last month that the upcoming tenth season of Keeping Up With the Kardashians  will "follow my journey of trying to get pregnant for the second time, which has proven not to be as easy as the first time, but we're working on it."

Keeping Up With the Kardashians Season 10 premieres March 15 at 9 p.m. only on E!