This was a little confusing. A few things that I'd suggest changing are:

This is when a whole becomes a half
And he rips her heart in two

I think it would be better to say:

This is when a whole becomes a half
As he rips her heart in two

It just flows smoother.

another thing:

"Things aren't the same", he says
Clearly not fighting any tears

Whose not fighting tears?

In this stanza is when I became really confused:

As her and her new beau arose
He was in awe to see her face
She introduced her new mate
And his heart began to race

Who is "he"? the new boyfriend or the ex?

Okay she and her new boyfriend are together...He.. the ex? is in awe to see her? But i thought he was done with her? the "new mate" sounds kinda funny... and the ... ex? or is the new boyfriend's heart that is racing? from anger or love?

And without clarifying who he is the ending is unclear. Does she get revenge from her ex by him wanting her back and her saying ha no. Or does she do the whole.. break up with the new boyfriend?

I believe once you get that straight things will be a lot better.

Sorry to totally bash on your poem lol I really did like the story and the emotion in it. You just need to smooth it out a little.

My favorite part was the last stanza the message was clear and the statement true.

I look forward to re-reading this once you revise it :)

I really liked the last stanza. I can relate to what you're saying. There have been times when I felt the end was coming but it still hurts the same and I was still shocked after. I think you did a very good job of telling their story and how their love fell apart. I love the flow of this piece as well as the imagey. Nice work dear. Nik

This poem kept me on the edge of my seat
Though the reality did not bother me, I had hope for a happy ending

well done

Short and sweet, I loved it! So true, irony and love clash together and when you look back, you realize that you may have let go of something over the smallest problem. "Too late" :)
I loved how you repeated your lines but broke them into different parts throughout the poem. THAT made this piece, and without that lyricism it wouldn't have worked, so bravo. You tied the two people together as one even when they weren't "one" anymore, which tells the reader that even when it's "over", it's never really over.
again, 5/5 :)