She finds Mark outside and ready to go, texting on his Blackberry. When he looks up from his phone he sees that she looks funny and asks if everything is okay. Lexie blurts out, "I love you!" and then her mouth drops open, appalled at herself. She stutters as she tries to explain herself and just winds up telling him again that she loves him with a manic giggle. She then begins to babble about how she kept trying to push her feelings down, and how Jackson is a great guy with a number of things that make him sound great on paper: hot, no grandkids, no baby with his lesbian BFFs, etc. But, she loves Mark too much for that ever to have worked out; she starts to cry as she tells him that she can think of nothing else but him, and can't even eat or sleep because she's so in love with him. Mark can do nothing but literally stare at her in shock, with his mouth hanging open. I suspect her timing is rather horrible based on his mysterious epiphany in the OR earlier. She finally pulls herself together and heaves a sigh of relief that it's finally off her chest, but he is now looking worried. She says his name, but just then Julia walks up, says hi to Lexie and asks Mark if he's ready to go. Lexie could not be more horrified at herself.
Arizona goes to visit Nick who is groggy but happy on the good painkillers. Once she determines that he's fine, she reads him the riot act for not calling her to help treat his cancer and going off to some quack (her word) in Tibet instead. He tries to argue that naturopathy is a viable option but given the state of his health I'd say it's not a very strong argument at just this moment. He keeps trying to make jokes but she in no mood for that and yells at him that he's dying. I'm not sure if he knew this yet or not but either way, his face falls. She's extra angry with him because he knew how horrible it was for them when Tim died so this just seems irresponsible when he could have gotten help earlier and avoided this fate. He asks, "Why do you think I didn't come sooner?" and then asks if she really thinks he doesn't know what this must be like for her. Huh? Dude, if you'd come sooner you wouldn't be DYING. And that is basically what she tells him: that she couldn't help Tim but she could have helped him, and he's an idiot. He gapes at her, at a loss for words. But seriously, had he not connected those dots until now? Well, he's a wonderful human being who helps orphans -- he's just not so good with actual logic and deduction, it seems. We all have our strengths. Arizona runs from the room and Callie happens to catch this from the doorway and looks worried.