Ashley Olsen, Alexa Chung, And More From The YSL Belle d’Opium Party

The YSL Belle d'Opium Party last night was set up to rival its 1979 Opium launch party (that famously included some mighty debaucherous activities at the South Street Seaport), but the affair last night was a decidedly more sedate event. A subtle haze, purple lighting, along with the heady scent made for quite a intoxicating experience. But that doesn't mean that the evening was without excitement; With a rotating, 3D theater that spritzed the scent as French actress and face of the fragrance Melanie Thierry writhed on screen, jugglers and card readers doling out entertainment from the evening, and Alexa Chung and Alexandra Richards DJing in an elevated booth from above, the evening was a circus of activity (made only more theatrical as The City started filming during the middle of the event). Maggie Gyllenhaal waltzed around in a strapless pink gown, Jeremy Scott pow-wowed with his group of young It Things including Cory Kennedy and Mark Hunter, and Ashley Olsen sipped her champagne while wearing a patterned doo-rag headscarf and a floor-length windbreaker jacket. Click through for the snaps from the evening! For more videos, party pics, and YSL goodies, visit What's Your Opium.