live the life of Reilly
To lead a life of great ease, comfort, or luxury. The phrase is likely of early 20th-century Irish-American origin, but to whom Reilly refers is uncertain. Pampered from a young age after his father came into sudden wealth, Jonathan lived the life of Reilly compared to the hardships his older siblings faced.
lead/live the life of Reilly/ˈRiley
(informal) have a comfortable and enjoyable life without any worries: He inherited a lot of money and since then he’s been living the life of Riley.