Hot with a hangover!

On Halloween night, Rihanna played hostess for a costume bash at Graystone supper club in West Hollywood -- with on-again, off-again beau Chris Brown among the guests.

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By Thursday morning, the "Diamonds" singer, 24, was ready to chill out at home in bed -- with nothing on, naturally.

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 "The morning after! Hello November," Rihanna wrote beneath a sultry new Instagram photo, in which she sits up in bed, topless, wearing just a viel with a crown from her princess-like costume from the evening prior.

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Although Rihanna's nearly naked Thursday morning look raised more than a few eyebrows, it was Brown's Wednesday night costume that really shocked: The "Don't Wake Me Up" singer, 23, dressed up as a member of the Taliban, complete with white face makeup, traditional dishdasha garment and turban, with ammunition strapped to his chest and a pistol in his right hand. In an Instagram photo, Brown was flanked by four pals similarly garbed as Arabic terrorists.

This article originally appeared on PICTURE: Rihanna Goes Topless in Bed Morning After Halloween