Marshall and Lily think that they want to have a baby, Barney invents a holiday for men who are single, and Ted and Robin argue about the pros and cons of having children.
This episode provides examples of:
- Alcohol-Induced Idiocy: Lily, while drunk, goes to the GNB HQ to seduce Marshall. Hilarity Ensues.
- All Guys Want Cheerleaders: According to Barney, the "cheerleader effect" is the reason for this: supposedly, cheerleaders only look attractive as a group.
- Babies Make Everything Better: Discussed and zig-zagged throughout the episode. Lily initially thinks this way, thinking babies are adorable, but later becomes conflicted because of how much work she'd have to do to support the baby. Of the gang, only Ted, naturally, thinks having babies is a natural and wonderful part of life.
- Baby Fever Trigger: Lily and Marshall's story arc about having children kicks off when they start to get baby fever from all the cute babies they see. Marshall meets their neighbor's new baby, Jeremy, and is overcome by how cute his tiny sock is. While Lily initially holds back on having kids (since she actually spoke with Jeremy's exhausted mother while Marshall played with Jeremy), when she gets drunk and sees the sock herself, she foregos all logic and decides to try and conceive a baby with Marshall right at his workplace (though once she sobers up, they both decide to wait a while). Both Barney and Robin (who both insist they don't want kids) go into Cuteness Proximity as well when they come across the sock.
- Call-Back: Barney explains the "cheerleader effect" (where a group of women seem hot when individually they are not) at the beginning of the episode. At the end, Ted makes him take a closer look at the "cool bros" he's hanging out with.
- Cross-Cast Role: One of Marshall's two Identical Strangers this episode is a woman also played by Jason Segel in drag.
- Cuteness Proximity: At various points throughout the episode, the main cast all find themselves cooing over a little sock belonging to Marshall and Lily's neighbour's son. Even Robin and Barney, who are strictly opposed to having kids, can't help but gush over it, unable to say anything but, "sock!"
- Description Cut:
- Robin says that Ted acts like the group's dad, and every example she gives is punctuated by a flashback to Ted exhibiting the mentioned behavior.
- Later, in the cab, every time Robin lists a reason why babies are impossible to deal with, the camera cuts to drunk Lily performing a similar action.
- Distracted by the Sexy: Lily, after her Alcohol-Induced Idiocy, goes to GNB HQ and repeatedly attempts on seducing Marshall. Additionally, Marshall's client sees her too. Luckily for Marshall, he doesn't realize that she's with Marshall.Marshall's client: (to everyone else in the meeting) Did anyone else see the drunk chick?
- Event Title: Barney suggests to have the titular "Not A Father's Day" for what he believes are "single guys by choice".
- Fan Disservice: Lily crashing Marshall's office and coming onto him in a skimpy nightie would be a pleasant sight, but it's made ridiculously unattractive because she's so wasted that she's acting like an infant.
- Foreshadowing: The Stinger is the very first glimpse of Barney's Daddy Issues. Additionally, his pregnancy scare is also a glimpse of the Grand Finale.
- Identical Stranger: Marshall has two doppelgangers; one a woman included when Barney explains the "cheerleader effect" to the gang, the other included in the group of men Barney is hanging out with near the end of the episode. Strangely, neither of them are Marshall's official doppelganger.
- Interrupted Intimacy: Marshall and Lily's attempt to have sex on the couch is thwarted when a depressed Robin comes in to watch some television.
- Lingerie Scene: Lily arrives at Marshall's office in lingerie so they can conceive a baby right then and there.
- Orphaned Punchline: Subverted. Robin notes that Ted "always tell[s] super-corny dad jokes", and the camera cuts to Ted saying a punchline to the group and laughing by himself. Then, Robin says that Ted interacts with waitresses in a lame way, and we cut to Ted asking a waitress the opening to the joke.
- Sexy Discretion Shot: Lily strips down naked but only the lingerie she takes off is shown. Lily herself is blocked behind a wall.
- Team Dad: Lily and Robin call out Ted that even though he doesn't have kids he still acts as a dorky dad to everyone. Ted hastily denies it, but a few flashbacks and a snarky remark from Ted confirms it.Lily: Ted, you may think you're single and childless, but you're totally a dorky dad.Lily: (squirms as if she is his daughter)
