Love the One You're With

Music
This episode's title originated from the song , originally sung by .

Main cast

 * Ellen Pompeo as Dr. Meredith Grey
 * Sandra Oh as Dr. Cristina Yang
 * Justin Chambers as Dr. Alex Karev
 * Chandra Wilson as Dr. Miranda Bailey
 * James Pickens Jr. as Dr. Richard Webber
 * Sara Ramirez as Dr. Calliope 'Callie' Torres
 * Kevin McKidd as Dr. Owen Hunt
 * Jessica Capshaw as Dr. Arizona Robbins
 * Sarah Drew as Dr. April Kepner
 * Jesse Williams as Dr. Jackson Avery
 * Patrick Dempsey as Dr. Derek Shepherd

Guest stars

 * Eric Dane as Dr. Mark Sloan
 * Adina Porter as Dr. Ramsey
 * Gaius Charles as Shane
 * Tina Majorino as Heather
 * Jim Turner as Dr. Schacter
 * Elizabeth Tobias as Boise Chief