。
The story was so funny we were doubled over laughing.
Literal
Story [topic-は] belly [object-を] hold [and-て] laugh [degree-ほど] was-funny.
~ほど ('to the degree that') sets up a comparison of intensity. 腹を抱えて笑う ('laugh holding one's belly') is an idiomatic expression for uncontrollable laughter — the Japanese equivalent of 'doubled over.' The degree clause precedes the adjective it modifies, the opposite of English word order.