Letters to a person I'll never send

Jealousy

Your face with hers.
Sparks something in me.
Sets fire to something deep in my chest.
Low in my stomach.
In the center of my heart.
The spark lights little pieces that have always been there.
It turns into a blaze.
She's smiling.
I can see it.
I'm in a different world compared to you,
but even still I can feel it rise.
She knows what she's doing.
I know what she's doing,
Do you?
Are you in on it?
Doesn't matter.
You're mine.