News came earlier today that a clip from "X-Men: Days of Future Past" will be attached to the end credits of "The Amazing Spider-Man 2" in both the United Kingdom and the United States.
Now, Variety has details on how the cross-studio deal came about and it's all due to contractual obligations.
Director Marc Webb had an existing contract with Fox Searchlight to helm another film following 2009's "500 (Days) of Summer." In 2012, Webb's negotiations with Sony to helm "The Amazing Spider-Man 2" stalled due to his Fox commitment.
Fox agreed to allow Webb to direct Sony's "Spider-Man" sequel, but on the condition that Sony would promote its "X-Men" film for free with the stinger.
Despite the appearance, no "X-Men" and "Spider-Man" team-up movie is planned.