WTF!! Amber Rose files for Divorce from wiz Khalifa [See More]

In a shocking new development,Amber Rose has filed for divorce from Wiz after one year of marriage.  According to TMZ....

In the divorce docs -- obtained by TMZ -- Amber says they split on Monday and cites irreconcilable differences.

Amber is asking for full legal and physical custody of their 1-year-old son Sebastian. She's willing to give Wiz visitation.

And this is interesting. Amber acknowledges there's a prenup, which you would think would work in Wiz' favor, but she says it's valid ... presumably, she's not challenging it. The docs say the prenup provides spousal support.

As for why they split, there's been a buzz over the last few days of infidelity, but there's no mention of it in the papers.

Heartbreaking.......