It was "Secretary's Day" at Dunder-Mifflin, and that meant one of the first Erin-oriented episodes of The Office. For the most part, it was a big hit ... foster home issues aside.

While spending most of an episode on Andy and Erin, rather than having them as a cute side plot, was a risk, the show delved into her character and made us love her more.

The show can pull off an episode like this because it's spent years building up these characters, and integrating the new ones so seamlessly. Andy Bernard is a prime example.

Andy is such a walking riot that we often forget he was once the new guy too, and that he was engaged to Angela. This long-buried fact reared its ugly head Thursday night.

Naturally, it was Michael Scott who did the rearing.

Erin did not know about this, and it triggered a meltdown so well-played by Ellie Kemper, we didn't know whether to laugh, cry, roll our eyes or what. In short, vintage Office.

Last night's episode definitely didn't damper our crush on Erin.

If nothing else, this plot line dispelled the notion that Andy and Erin are just a bizarro world Jim and Pam, which was great. We've wanted them to become a bit more complex.

Speaking of Jim and Pam, breastfeeding was once again a huge topic of cringe-worthy humor, but the night's biggest laughs belonged to Oscar, Kevin and ... Cookie Monster.

Oscar's idea to dub Kevin's voice over the Sesame Streeter was hilarious, making you wonder if they thought up years ago and just withheld it until they had 10 minutes to fill.

Miffed, Kevin took his beef to Gabe, which was also fun as it gave the Sabre lackey a chance to really assert his non-authority. Classic office antics and well done all around.

It was a great night for The Office quotes, but before we get to those, some random thoughts:

• It's the third week now. Dwight prepping to help Pa , Meredith using her apparatus in the bathroom ... how long can the writers milk (har har) the breastfeeding jokes?
• The disturbing lack of Creed was almost made up for by Ryan walking around with an untied bow tie for no explained reason ... these little Office nuances just kill us.
• Angela smiling at the Cookie Monster video, saying "This is my favorite day" ... ROFL. Also funny? How unfunny the retaliatory video featuring Oscar as the count was.
• Andy at a loss for words - or more accurately an upbeat song, a cheesy, over-the-top romantic overture or Cornell name-dropping opportunity - that's gotta be a first.

Follow the jump for classic quotes from "Secretary's Day" ...

Erin: In the foster home, my hair was my room. | permalink

Dwight: Three squeezes and I would drain you. | permalink

Kevin: They're making fun of Cookie Monster, I get that; but in a weird way, it's like they're making fun of me. | permalink

Erin: I think I have to be on my own a little bit, like Precious, that girl from Precious: Based on the novel Push by Sapphire.
Andy: I didn't see that movie. | permalink

Meredith: This is like the Cadillac of breast pumps. | permalink

Andy: I resent the implication that I would keep that secret. I can't and I won't. | permalink

Erin: I liked April when I was 7. | permalink

Angela: [watching Cookie Monster video] This is my favorite day! | permalink

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.