Sometimes, the hardest part about friendship is telling your best friend something you know she won't agree with. Because real best friends watch your back when you're laid bare and are at your most vulnerable. They shield you, figuratively and literally.

Best friends - if they're really friends - know when it's time to give you a reality check.

And when to just shut up and listen.

"What's with green tea?" Meredith asks, as she and Cristina walk on the hospital patio toward a table.

"I don't know. The coffee Callie made this morning smelled like a chemistry experiment gone bad. Turned me off to coffee for the rest of the day. And by the way, I'm seeing Owen again."

"You're what?" Meredith plants her plate of cranberry orange muffins on the table with a clatter and glares at Cristina.

"Shhh. Could you keep it down?" Cristina snaps back, looking around to see who has noticed their exchange.

"I can't believe what you just said. You're seeing Owen again? Isn't it too soon for that?"

"It's not like I'm sleeping with him. We're just taking things slowly. Very slowly."

"Oh, you mean like holding hands? Lovely."

"Derek called you a lemon. He threw a bat at you. Never really apologized. And you didn't think twice about taking him back."

"It's not the same thing. And you know it."

"You're right. It isn't. If Owen wasn't doing anything about what happened, we wouldn't be talking about this now. But he is. What's Derek doing about the things he said and did to you?"

Meredith stares at her before replying, "Cristina, we're not talking about Derek."

"Owen's been seeing Dr. Wyatt for what, seven weeks now? I just started seeing her myself. "

"You two are seeing Dr. Wyatt? What else are you going to tell me? You're having premarital counseling?"

Cristina takes a sip of green tea.

"I'm seeing her on my own."

"Oh."

"Did you ask her if it's ok for you to start seeing Owen again?

"No. I decided that on my own."

Meredith sighs.

"I just don't want you to get hurt."

Cristina finishes her lemon bar and eyes the muffins on Meredith's plate. "I know. Are you going to eat those? Because if you're not, can I have them? I'm so hungry."

Meredith slides the plate across the table toward Cristina, who promptly breaks off a muffin piece, and pops it into her mouth.

"So, was it really that good?" Meredith asks, pretending to be annoyed.

"What was good? The muffin? Yeah, it's good."

For the first time since they sat down, Meredith grins.

"The sex, silly. I mean, don't take this the wrong way, but it's been a while for you."

Cristina gives her that rare, beatific smile, her eyes looking far away, her mind, her body, remembering all too clearly.

It's Cristina's turn to sigh.

"That good, huh?" Meredith teases, her grin widening. "C'mon. He'd better be worth all the trouble you've gone through."

Cristina frowns.

"I meant your visit to Dr. Wyatt."

"Has anyone ever touched you, made love to you that you find a part of yourself you never knew was there before?"

Meredith smiles, says nothing and looks at her coffee cup. She brings the cup to her lips and looks at Cristina again. Something had changed.