What is the ruling on playing music or watching movies in a room where there is a closed Mushaf, and is this considered mockery of religion or merely a sin?

Playing forbidden songs and music and watching impermissible films is not allowed and is haram (definition) at all times and in all places. As for the mere presence of a Mus'haf (copy of the Quran) or a storage device containing the Quran in the same place where these forbidden things are being played, without the Quran being played at the same time, this is not considered mocking the religion. Mockery is defined as belittling and showing contempt, and this act does not involve belittling or ridicule, even though it is a sin in itself. One must be wary of the devil's whisperings.