A cinema in California has been forced to issue an apology after accidentally showing a trailer for the adult animated film Sausage Party at a screening for Finding Dory. Families had turned up to see the sequel to Pixar's 2003 smash hit, Finding Nemo, expecting to see some PG-rated action. But after a manager clicked on the wrong movie in the weekend rush, they were 'treated' to a sneak-peek of the forthcoming adult animated comedy instead - along with its x-rated language. Sausage Party, which is said to be rated R in the USA (under 17s require accompanying parent or adult guardian) was written by comedian Seth Rogen, who has previously starred in films Knocked Up and Superbad.