Lyrics:

A man is in love, how do I know?
He came and walked with me, and he told me so
In a song he sang, and then I knew
A man is in love with you

A man is in love, how did I hear?
I heard him talk too much whenever you're near
He whispered your name when his eyes were closed
A man is in love and he knows

A man is in love, how did I guess?
I figuered it out while he was watching you dress
He'd give you his all, if you'd but agree
A man is in love and he's me