Kylie Jenner sported some seriously sexy leather lace-up pants Monday during a shopping spree in West Hollywood ... and to top it off, some seriously sparkly bling!

Kylie just luuuuuuvs to flaunt her diamond promise ring -- or whatever it is -- from Tyga. Seems to us she likes to pretend she's married; and for all intents and purposes, she is! That said, we can imagine what her wedding will look like one of these days when wedding planner to the stars, Kris Jenner, decides to finally let her youngest tie the knot. Yowza!