It's rude to have someone wait for you.
Steve promised to meet Laura at the library at 7pm to study for a test, but he's feeling hungry.
Steve wants to get something to eat.
Steve gets something to eat at the cafe in the library.
Steve stops at a pizzeria on the way to the library.
Steve makes it to the library on time, and he and Laura start studying at 7pm.
Steve is late, and Laura and Steve don't start studying until an hour after 7pm.