Going to Denmark
Codeword for having sex so other attentive listeners do not catch on to the underlying message of the conversation. Other destinations can be used instead of Denmark to symbolise different sexual activities such as Canada or London (Foreplay and kissing respectively). A person can also be taken to Denmark unwillingly in which case it can be expressed as 'getting kidnapped to Denmark'.
See that guy over there? I'm going to Denmark with him soon