I figured this out by ear last night while I was listening to it for the first time in a 
few months. I think the original is by Paul Collins, but The Exploding Hearts covered 
it a few years ago and that's the version I know best.

Intro:
E                D               A
E                D               A

Chorus:
E               D               A
Oh why are you walking out on love?
E               D               A
Oh why are you walking out on love?

Verse 1:
Em
Why are you leaving,
You're saying goodbye,
Why don't you stay,
And give it one more try?

D                                 B
Why when you were happy here with me?

Chorus:
E               D               A
Oh why are you walking out on love?
Oh why are you walking out on love?

Verse 2:
Em
Gimme the reason,
The truth of my lies.
You're saying you love me,
Now you're saying good bye.

D                                 B
Why when you were happy here with me?

Chorus:
E               D              A
Oh why are you walking out on love?
Oh why are you walking out on love?

Verse 3:
Em
Why are you leaving,
You're saying goodbye.
Why don't you stay,
And give it one more try?

D                                 B
Why when you were happy here with me?

Chorus:
E               D               A
Oh why are you walking out on love?
Oh why are you walking out on love?

Outro:
D               A
Walking out on love.
D               A
Walking out on love.
D               A
Walking out on love.


I hope you have a killer time playing this, and I hope this tab helped you.
Stay groovy and keep on rockin'!