Halloween isn't just a time to trick-or-treat or begin your apology tour for wearing a "culturally insensitive" costume (looking at you, Hilary Duff).

As demonstrated by gorgeous celebrities like Emily Ratajkowski, it's also a once-a-year chance to dress up in some seriously provocative apparel, on a very special night when women are exempt from "slut shaming."

The best from this weekend was a mix. There were plenty of classics, like Demi Lovato as Dorothy, some more topical ones, like Kelly Gale as Suicide Squad's Harley Quinn, and some true strokes of creative genius, like Martha Hunt, who was on fire as ice queen Elvira Hancock from Scarface. But all worked the sexy angle to the hilt.

Below, browse the hottest costumes from last weekend's Halloween festivities:

Demi Lovato as Dorothy

Martha Hunt as Elvira from Scarface

Jasmine Tookes as Princess Jasmine

Emily Ratajkowski as Cleopatra

Kylie Jenner as Christina Aguilera

Mariah Carey as a fallen angel

Taylor Hill as a "demon from hell"

Lais Ribeiro as a sexy possessed nun

Shanina Shaik as Morrigan Aensland

Kelly Gale as Harley Quinn

Alexis Ren as ???

Ariel Winter as a sexy bunny