《But I Do》是歌手Bob & Marcia于2010年3月1号发布的一首流行音乐，归入专辑

(I Don't Know Why) But I Do
　　I don't know why I love you but I do
　　I don't know why I cry so but I do
　　I only know I'm lonely and that I want you only
　　I don't know why I love you but I do
　　I can't sleep nights because I feel so restless
　　I don't know what to do, I feel so helpless
　　And since you've been away, I cry both night and day
　　I don't know why I love you but I do
　　My days have been so lonely
　　My nights have been so blue
　　I don't know how I manage, but I do
　　Each night I sit alone and tell myself
　　That I will fall in love with someone else
　　I guess I'm wastin' time but I've got to clear my mind
　　I don't know why I love you but I do