The episode begins and Marshall and Lily have brought Marvin to the bar. He's teething on jalapeño poppers. Ted offers to watch Marvin, and Marshall accepts. Barney drips some ketchup onto his fancy red tie, which he mourns as it endures its final moments. Robin is acting like a schoolgirl trying to get the quarterback's attention. Lily pulls Robin aside and gets the scoop on the fact that Barney told Robin he was over her and wouldn't chase her anymore. Lily realizes it's a "classic lobster situation", recalling when Robin was told she was allergic to lobster and she responded by eating a bunch of lobster while her face swelled up and a rash broke out.
Lily tells Robin she cannot ever go after Barney. Robin again sets up some time alone with Barney by pretending to have invited the rest of the group to hang out with them and then saying they all couldn't make it. She proceeds with her schoolgirl thing until her inner voice of reason tries to set her straight. Barney is having a tough time with his tie's death, and when he gets a lobster bib he realizes that he could have just had the best idea ever: ‘Bro Bibs’ a bib that looks like your suit and tie but protects them. Lily meets Robin at the bar and agrees the Bro Bib thing is a great idea, but doesn't really respond to Robin's Barney situation.
Lily leaves to check on Ted, who is watching Marvin in the apartment. Lily arrives and Ted tells her that Marvin crawled. He took a video of it, but he had the camera flipped to face him. Lily cries, while Ted goes to check on Marvin in his room, because she missed Marvin's first crawl. Marshall assures her they'll see the next one, and Ted calls out from the room to say Marvin's crawling again. Lily cries some more. Lily misses more crawls, but Marshall assures here there are lots of other firsts that they'll see. Lily points a camera at Marvin and insists that he crawl. Robin drops in and says she really needs to talk to Lily. They go to the bar, where Robin uses the lobster analogy to explain to Lily that like she did with the lobster she needs to get Barney into her one last time so she'll never want him again.
Robin goes through a few attempts to get Barney. She tries "the damsel in distress"’ by asking him to rush to her office to help with her printer. When that doesn't work, she tries to make him jealous with guys drooling over her at the bar, but Barney just uses the opportunity to market his Bro Bibs to the guys. She tries looking like Angelina Jolie by putting on her best Lara Croft impression at laser tag, but Barney just thanks her showing up by using her as a human shield and running away from laser shooters. Then Robin asks Lily for help and Lily recalls getting freaky with another girl back in college to get Marshall's attention. Lily thinks she and Robin will be doing this together, but Robin brings Brandi Worldwide News' weather reporter to the bar and gets freaky with her.
It works, but Brandi is the one Barney leaves with, heading to the studio so they can do it in front of the weather map. The next day, Marshall tells Lily that Ted took Marvin shopping and bought all of his winter clothes. Lily cries. Ted brings Marvin out and shows him wearing a Cleveland Browns “onesie”, which makes Marshall cry. Ted tells them he moved his meeting the next week so he could watch Marvin. When he's told that Lily's dad Mickey will be better by then, Ted tells them he gave Mickey the month off because it's supposed to snow and he doesn't want to miss Marvin's first sleigh ride. Marshall and Lily fire Ted. Ted eats with Barney at the bar both of them wearing Bro Bibs when Marshall and Lily call him to apologize and invite him to join Marvin at "Bubble Buddies".
When he gets there, Marshall and Lily tell Ted that he's been overdoing it a little with Marvin. They found the "Baby's Book of Firsts" scrapbook which included Marvin's first visit with Santa Claus, enraging Lily and it reminded them of Ted's other scrapbook, his building's book of firsts. They realized that Ted's GNB project was his baby, and now he needs another project. They rescheduled Ted's meeting with the headhunter and its there at the Bubble Buddies class. Barney gets to the bar to tell Robin and Lily that he didn't end up hooking up with Brandi. He realized that he's been doing weird, desperate things since Quinn left. He leaves and says he'll figure it out.
Robin tells Lily she feels bad because Barney's going through some serious stuff and she's been more worried about herself. She says she's going to give him some space. Next, Robin is seen at Barney's apartment door, attempting to seduce him in lingerie. But Patrice is there and Barney explains that the night before, when he went to the studio with Brandi, he ran into Patrice. She could tell that he was sad and they talked all night. He says they're "kind of on a date right now". Robin leaves.
At the bar, Ted apologizes for going too far with Marvin's firsts, the Santa thing, especially. A few years later, Ted is seen dropping his little girl off with Aunt Lily and Uncle Marshall. As soon as Ted leaves, they get the little girl ready to go see Santa for the first time. The episode ends at this point.