MARION COTILLARD AND GUILLAUME CANET Marion Cotillard has had more than one partner, both on and off screen. She dated actor Julien Rassam in the 1990s. She then had a five-year relationship with Stéphan Guérin-Tillié, who co-starred with her in the 2000 film "A Few Days Too Many." Marion Cotillard then dated singer Sinclair, or Mathieu Blanc-Francard by her real name, before meeting Guillaume...