Love, Awkwardness, and Moonlight: As Told by a Third Wheel

We stand by the wall, three shadows in the splash of moonlight.
He lifts her to the window, and she disappears gracefully into the darkened house.
Next he helps me up, and I blush at his touch, and fairly tumble onto her bedroom floor.
Finally he climbs in with us, closing the glass behind him, shutting out the balmy night air.
They lie on the bed, hand in hand, and smile at me unconsciously.
I sit down on the wood floor, not knowing what to do.
They wrap their arms around each other.
They kiss lightly, and talk, and laugh.
I banter, I tease, I wait, though I don't know what I wait for.
I suppose I'm jealous.
Images run behind my eyes:
another boy, another girl, another place,
but the same moonlight that shines on us now.
I suppose that's the problem.
I had what they have, once.
In my childishness, it seems an injustice that they should be together, and happy,
while I sit alone and watch them fall in love.
They try as hard as they can not to make me feel unwanted.
They pull me onto the bed with them and ask me what's wrong.
But what can I say?
I laugh and shake my head, alarmed at the tears forming in my eyes.
She plays with my hair with the hand that's not clasping his;
He gives me advice on long-distance relationships while he holds her close.
I close my eyes and try to concentrate on the cool air that wafts from the vents,
blowing away the warm mists that crept in from outside.
I hear him say he has to go.
Am I relieved, or disappointed?
I wish I knew.
He opens the window, pauses, looks back; she slips into his arms.
They press their lips together.
I turn away.
There is a long silence, then a brush of cloth over glass and a soft click.
He is gone, and she and I are left behind.
She gazes out the window, out at the tall grass rustling under the stars.
I sit alone at the foot of the bed, a shadow in the quiet moonlight.