Depending on how harsh you want to be, and/or the reasons for the breakup:
Touch Me In The Morning - Diana Ross
Touch me in the morning, then just walk away
We won’t have tomorrow, but we had yesterday
Fifty Ways To Leave Your Lover - Paul Simon
Just slip out the back, Jack
Make a new plan, Stan…
Already Gone - Eagles
Just remember this my girl, when you look up in the sky
You can see the stars but still not see the light
Runaround Sue - Dion
If you don’t wanna cry like I do
Keep away from Runaround Sue
Angie - Rolling Stones
Angie, Angie
Ain’t it time we said goodbye?
I’m Looking Through You - Beatles
Why, tell me why will you not treat me right?
Love has a nasty habit of disappearing overnight
Tainted Love - Soft Cell
Once I ran to you – now I run from you
This tainted love you’ve given
I gave you all a boy could give you
Take my tears and that’s not nearly all
And just to prove I’m not (just) some kind of Classic Rock jukebox,
Gonna Eat Them Words - Mojo Nixon & Skid Roper
Woman said I was no good - never have no cash
Get a thousand silver dollars - ram 'em up her AAAASSSS