This is the point where Lily crosses the line for me. There's a lot to like about the character. She is feminine without falling into stereotypes, unique within the group without descending into "cool girl" cliches, and enjoys sleeping with her significant other with no shame or compunction about it. And yet, as the show aged, as happens with any sitcom, her character has gotten shaggier.
But maybe there's a trend that can be traced to before the show, which had just crossed the halfway mark of its lifespan by the time "The Front Porch" rolled around, began to chip away at her more admirable qualities. Namely, Lily has consistently shown an inability to be straight and candid with the people she loves, preferring to try wild schemes to avoid having to do so. Now that's a symptom of many sitcom characters, but it's especially salient for Lily.
In the first season, Lily considers going to an art program. There's nothing wrong with that, and it's quite sympathetic to think of her as having been caught in a whirlwind that pushed her life in a particular direction, and at the precipice of a big moment that generally causes people to reflect on the path that brought them to a particular place, she begins to question if there were opportunities she missed. The problem is that she doesn't tell Marshall that until she's applied, interviewed, and sworn Ted to secrecy over it, a scant bit of time before their wedding. She gussies up the plan in the guise of self-assurance that she could do it, not that she actually would, but it's a poor attempt to paper over her withholding something important from her fiance.
This progresses in the third season, to where Lily not only fails to tell, and has never told Marshall, about her crippling credit card debt, but then subtly steers him away from his dream job and toward a bland corporate position in order to pay for it. What's more, she doesn't tell him about this when the two of them are making a massive financial commitment in purchasing an apartment until she's forced to by a horrible credit report, and even that she tries to back her way out of.
And in many ways, "The Front Porch" is the final straw, in which it's revealed that rather than confronting Ted (or Robin for that matter) directly about her concerns about the women he's dating, she takes matters into her own hands and meddles and sabotages and enforces her will on Ted and Robin because she thinks she knows best and because she doesn't want her eventual foursome between her, Marshall, Ted, and Ted's future wife to be insufferable to her.
It's horrible because it completely ignores Ted's autonomy. It's horrible because even if she claims she's just looking out for Ted, there's a clear element of selfishness to it. And it's particularly horrible in the case of her steering Ted and Robin toward the fight that would break them up because it's a clumsy retcon that cheapens the arguable peak of the show and one of its most significant moments. Some allowances must be made for the usual sitcom wackiness, but this is a trend, of Lily taking matters into her own hands, of Lily making major decisions without consulting the people affected by them, and of Lily deciding that her judgment supersedes anyone else's.
Now Lily is not alone here. Barney has consistently done far worse things, and he and Marshall pull a similar ruse in the next episode. But Barney occupies a unique cartoonish space that softens the blow of his behavior, and his and Marshall's plan seems to have more genuine altruistic intentions behind it. Lily, by contrast, may mean well, but her actions come from a place of self-preservation and disregard for the feelings and will of the people she cares about. Her apology is nice, and she's still a vital part of the show's incredible cocktail of personalities, but it's hard to look at her the same way after "The Front Porch."
Thankfully, the show adds a spoon full of sugar to help that bitter medicine go down. The wacky things that happen on Robin's morning show while Ted and Lily are hashing out the history of Lily's sabotage create some tonal inconsistency, but it's still a delightful background gag that's a bit lumpy, but still helps add some welcome levity to the serious conflict between the show's two leads. At the same time, Marshall and Barney's B-story about the merits of a Pajama Suit vs. a Nightshirt is equally wonderful and hilarious, with Barney's digs at the nightshirt being easy but fun, his eventual conversion was a hoot, and their tender moment (followed by a Night Before Christmas sequence together) strikes the right balance between goofy and sweet. [SPOILERS for the end of the series from here on out.]
But there's something else notable about "The Front Porch". Its final scene features a romantic dinner between Robin and Ted, where they contemplate what their relationship would be like if Lily hadn't interfered. And they're sweet with one another, and they still laugh and have that easy rapport and chemistry that made their relationship fun even as we knew it was ultimately doomed from the first episode. And you wonder for a moment if, after the feint of Ted and Robin's platonic sex from earlier in the season, the show will put them back together.
Instead it pivots, and when it seems like they're going to reunite, the two of them agree on a half-measure. At Robin's suggestion, Ted proposes to Robin as a "backup wife" (the words every woman always dreams of hearing), and the two of them giggle and the show plants the seeds for a way their romance could bloom down the line.
That scene has added weight now, knowing that the series ends with Ted and Robin reuniting in the future and semi-making good on that promise. If the show had ended after this season, that ending would feel more right than it ended up feeling for wide swaths of the fanbase. We were not as far removed from Ted and Robin's romantic bliss, left to wonder if their relationship might have blossomed were it not for Lily standing in the way, and reminded us of their connection and the way it might work at a different place in their lives.
The show would spend the ensuing five seasons going back and forth on that idea so many times that when it came time for Carter & Bays to make good on the ending they'd had planned since Season 2, it felt like a betrayal of years of character development that suggested Ted and Robin were not right for one another at an elemental level. In that sense, Lily feels like some sort of meta, utilitarian hero, trying in vain to prevent the outcome that the fans would eventually revolt against. But in the salad days of Season 4, where there was enough lingering goodwill for the Ted and Robin pairing, that final scene of the episode makes sense.
I'm still not a fan of the ending of How I Met Your Mother. It contradicts too much that happened in the show between when the series's creators decided on that outcome and when it came time to actually put it forward, and demands the sort of contextualization that likely contradicts what they intended when they offered it. But it does soften my view, and make Ted and Robin's eventually romantic reunion something the show at least meant to build toward, rather than a sharp left turn after a downward slope.
Lily is the worst character in the show. I know when you really think about it she meant well with causing some breakups of Ted's relationships, but I don't care. Because of her everyone was focused on the argument between her and Ted which made none of them pay attention to watching Robin's show, the whole reason they were all there. And of course, Robin somehow isn't pissed off at Lily knowing she's the reason for that and the reason for her and Ted breaking up. She's a manipulative bitch and somehow Ted's the only one who gets annoyed at her.