Who's Sienna Miller dating? It reportedly happens to be New York model Nico Malleville. The two are said to have had a romantic holiday to the Coqui Coqui spa in the Mayan Riviera, Mexico before then flew back to New York.
Sources said "The spa was the perfect retreat for them. It's like your own personal tropical hideaway, so it was ideal for Sienna and Nico to get to know each other better away from prying eyes."