Mark is still at the table, staring skeptically at Sloan, and as Callie finishes up taking blood she breaks the silence to point out that now would be a good time for him to say something. He doesn't, so Sloan asks if he's high. I don't think she's trying to be funny, I think she really is asking, but they are interrupted by Derek, who wants to talk to Mark. When he says "Sloan," Sloan thinks he's calling her name and looks absolutely delighted for a second, and already it's obvious that we're supposed to realize she's kind of a mouthy twit.
As they walk, Mark finally finds the power of speech again and freaks out more about how old this makes him rather than about the fact that he has a daughter running around. Derek, however, wants to talk to him about Nicholas and how he and Arizona need Mark's help. Mark's upset that he doesn't get more time to pout.
Cristina, Mere and Alex are hanging out in the skills lab and Mere and Cristina are eating and Cristina declares this the best Thanksgiving ever, since there is no family, traditions, or saying what one is grateful for. Alex in fact wants to do the opposite -- say what they are not grateful for, and naturally Cristina brings up the merger and Mere mentions the Mercy Westers themselves. As they gripe, Alex is practicing a stitch and Mere corrects his technique. The talk turns to her new mentor, and Cristina chalks it up to her daddy issues (though wouldn't that be her asking the Chief to be mentor and not the other way around?) while Alex calls her the Chief's bitch. Wow, that has got to be my least favorite new gag on this show, just because it was barely funny the first time and is now even dumber. Alex and Cristina start to bicker until Meredith shuts them down and goes back to helping Alex.
Lexie, Callie and Arizona, meanwhile, have gotten to leave the hospital and are at home preparing Thanksgiving dinner. As Lexie chops celery, Mark walks in the door and they all smile, but the smiles fall a little when Sloan follows him in. Callie asks who wants wine and Sloan immediately says she does, but Mark shuts her down -- now we know she's not just mouthy, she's a mouthy underage drinker. Mark announces, with a lot of forced cheer, that the results came back and that he really is Sloan's dad, and then tells them that he's invited Sloan to move in for a little while. Lexie is so... thankful to hear it that she chops off the tip of her finger and barely notices that she's now bleeding all over the celery. Aw, man! Now what is going to add a bit of crunch to the stuffing?