Rihanna celebrated Halloween by dressing up as the Queen of Ganja, but she celebrated the day after Halloween by dressing down as the Queen of Sexy! The singer recently posted (yet another) half undressed pic to her instagram, stripped except for her green veil. Riri’s future wedding (un)dress, we wonder? ”The morning after! Hello November,” she captioned the sizzling photo. She had spent that night living it up at her Halloween party, held at West Hollywood’s Greystones Manor. She arrived with friends Shaniece Hairston, and Basketball Wives star Evelyn Lozada, but soon was seen hanging with Chris Brown, who showed up wearing the worst costume of all time. Other guests included Paris Hilton, comedian Kevin Hart, and Lindsay Lohan, but Rihanna obviously stole the show in her costume that paid tribute to her favorite 4:20 pastime. Head down below for a better look at the hotness!