What does tom do when he and Daisy return from their honeymoon?

Nick learns from Jordan Baker the details of Tom's behavior in Santa Barbara after his and Daisy's honeymoon. She tells Nick that Tom was involved in a car accident that made the newspapers. He was with another woman, a maid at the Santa Barbara Hotel. Her arm was broken. This shows Tom's infidelity began early in his marriage and continued. Daisy was aware of it (everyone who read the newspaper was aware of it), but she remained in her marriage and gave birth to their daughter several months later.