What is we should catch up sometime?

"We should catch up sometime" is an informal way of saying that two individuals should meet up again after a period of time has passed since their last encounter. This phrase is often used as a casual greeting or conversation closer. It implies that the speaker enjoyed spending time with the other person and wants to continue the relationship. The actual timing and venue of the catch-up may or may not be decided upon during the conversation, but the phrase signals a desire for further communication or socializing.