Why is Due Date rated R?

Why is Due Date rated R?

Looking into the poster of Due Date with two men standing and one stout man holding a dog, you would say that it is a decent comedy movie. However, this was rated as R by movie review board because of its strong language and the content.
Due Date is an American comedy released in 2010. It stars Robert Downey, Jr. and Zach Galifianakis. It is directed by Todd Phillips. The entire film was shot in Mexico and Georgia. The film is about two men Peter and Ethan who met because of unavoidable incidence. The complications in the story started when Peter, played by Downey was about to go home and be with his wife when she gives birth to their first child. But then his luggage and wallet were sent to a different destination and was put on a no-fly list. He becomes desperate so he takes a hitch with Ethan (Galifianakis).
His journey, hoping he could reach the due date of his wife’s giving birth, was very unforgettable. He got into serious accident which fractured his bones, had to run from Mexican Police, and had suspicion of his wife’s affair with his friend. The problems just continued to pour for Peter.
There are parts in the movie which are not intended for children. There’s a scene of Ethan smoking marijuana and this caused Peter to be arrested because Mexican Police thought h possessed the illegal drug. The strong languages such as the exchange of words between the characters are also not suitable for children because these are indecent and offensive.
There are also sexual contents in the film such as the dog masturbating. Though the approach is funny, still that scene can be very unpleasant to the general audience.
In summary, Due Date may be a hilarious and entertaining movie but the sexual activity, violence, and curses involved are not appropriate for children and conservative audience.