In the chorus of Hot n Cold Perry uses antonyms to describe her partner 's mood changes , with the chorus of the song including the lines `` You 're hot then you 're cold / You 're yes then you 're no / You 're in then you 're out / You 're up then you 're down '' .
The song opens with Perry confronting her former partner over his frequent changes of mind , singing `` You change your mind like a girl changes clothes / Yeah you PMS like a bitch '' .
Hot n Cold