Looks like 11-year-old singer Willow Smith is growing up ... and fast!

The daughter of Will and Jada Pinkett Smith proudly showed off a tongue piercing in this snapshot while posing alongside a gal pal. At least we thought she had pierced it ... until she Tweeted the following: "It's fake... Sorry."

If the "Whip My Hair" singer wanted to actually get it pierced, she'd have to get consent of a parent or legal guardian since she's under 18 ... according to California law. We have a feeling Will nor Jada would be cool with it.

Oh, Willow!