This song by Panic! At The Disco is from their first album, A Fever You Can't Sweat Out. It is the seventh track. The full version includes a little bit if instrumental music at the end, which leads to the eighth track of Intermission. The song is about a boy whose girlfriend cheated on him. Ryan Ross (Panic! At The Disco's lead guitarist) said from an interview that he writes the songs about personal experiences he has…
Is it still me that makes you sweat?
Am I who you think about in bed?
When the lights are dim and your hands are shaking as you're sliding off your dress?
Well, then think of what you did