Outline:

Pick me speech: Okay, here it is, your choice... it's simple, her or me, and I'm sure she is really great. But Derek, I love you, in a really, really big pretend to like your taste in music, let you eat the last piece of cheesecake, hold a radio over my head outside your window, unfortunate way that makes me hate you, love you. So pick me, choose me, love me.

Meredith starts dating Finn. Never have sex.

Meredith finds out she's pregnant

She tells Derek- she's keeping it no matter what- he calls her a whore

MEREDITH: "I never should have told you about George."
DEREK: "No, its fine. I'm glad I know about him, and the vet. You really get around."
MEREDITH: "What did you just say to me?"
DEREK: "It's unforgivable."
MEREDITH: "I don't remember ever asking you to forgive me."
DEREK: "So, was the knitting a phase? Who's next? Alex? I hear he likes to sleep around too. You two have that in common.

Meredith: "You don't get to call me a whore. When I met you, I thought I had found the person that I was going to spend the rest of my life with. I was done! All the boys and all the bars and all the obvious daddy issues, who cares? I was done. You left me. You chose Addison. I'm all glued back together now. I make no apologies for how I chose to repair what you broke. You don't get to call me a whore."

She gets a DNA test

Shows Derek.

Mark shows up and flirts with Meredith (five months preg)

Derek punches him and signs up the divorcee papers

Addison leaved with Mark

Turns out to be twins

Older: Boy: Jacob Philip Sheppard

Younger: Girl: Alida Green Sheppard