Chorus:

Liar, liar, pants on fire
Your nose is longer than a telephone wire

Verse 1:

Ask me, baby, why I'm sad
You been out all night, know you been bad
Don't tell me different, know it's a lie
Come kill me, honey, see how I cry

Verse 2:
[ Lyrics from: http://www.lyricsfreak.com/c/castaways/liar+liar_20641863.html ]
Why must you hurt me, do what you do
Listen here, girl, can't you see I love you
Make a little effort, try to be true
I'll be happy, not so blue

[repeat chorus]

Verse 3:

If you keep on tellin' me those lies
Still goin' out with other guys
There'll come a day I'll be gone
Take my advice, won't be long

Verse 4:

When that day comes, won't be mad
Be free of you, but I'll still be sad
In spite of your cheatin', still love you so
I'll be unhappy if I let you go

[repeat chorus]