The phrase 'In Like Flynn' means that you have been quickly and / or emphatically successful, usually in a romantic context.
Example of Use: “How was your date with Sue?” Answer: “I was in like Flynn.”
Interesting fact about In like Flynn
The phrase 'in like Flynn' is a direct reference to actor Errol Flynn, who was famous for his romantic roles in Hollywood films as well as for his exciting, romantic private life.
