While promoting their upcoming boxing drama, The Bleeder, in Toronto September 10, Liev Schreiber told Us that working with love of 11 years Naomi Watts was “great. . . . There’s clearly a level of familiarity, and that really helped us.” Two weeks later, the actor, 48, and his NYC-based fiancée, 47, announced they had severed their romantic relationship. “It is with great love, respect and friendship in our hearts,” the parents of sons Sasha, 9, and Kai, 7, told Us in a September 26 statement, “that we look forward to raising our children together and exploring this new phase.” In fact, it has already begun. Since 2014, the two have mostly “lived separate lives,” says a source, while Schreiber filmed Showtime’s Ray Donovan in L.A. Adds a Watts friend,…