The O.C. Soundtrack 
Episode 13 • The Pot Stirrer
This song first comes on while Seth and Ryan talk in the Cohen's kitchen about Seth's college options. A little while later it plays at Kaitlin and Johnny are walking and talking on the pier, and finally it is played at the very end of the episode, as each character is left all alone, and Seth lights up.
C'mon, there's no such thing as a stupid question. Get the ball rolling and be the first.