History YMMV / LifeWithDerek

** The animosity between Derek and Casey is just as easily explained by their being two Type-A personalities competing for dominance in the household.
*** Their constant antagonism is also speculated to be the way through which they fight [[UnresolvedSexualTension their attraction to each other]].

** Casey and Derek seem more like they have BelligerentSexualTension than just SiblingRivalry most of the time.

* RelationshipWritingFumble: Derek's relationship with Marti frequently comes off less like they're siblings and more like parent and child.

** Marti can come off as this due to her SpoiledBrat status and her constant need to get her way.

* AcceptableTargets: The show preserves the grand Canadian tradition of making fun of Newfoundland. This could actually be a bit of an in joke, considering that ''that's where the first season was actually filmed''.

** And then there's Ariel Waller (Marti), who doesn't really resemble any of the main cast except for Joy Tanner (Nora).

* SpiritualSuccessor: It's the 2000s version of Series/TheBradyBunch and to a lesser extent Series/StepByStep.

* TastesLikeDiabetes: Marti.

* RelationshipWritingFumble:
** Casey and Derek seem more like they have BelligerentSexualTension than just SiblingRivalry most of the time.
** Edwin and Lizzie too, especially when they lock themselves in the closet together. The writers did attempt to avert this somewhat by doing things like having Edwin address Lizzie as "sis", though YMMV on how well it works.
** In a non-romantic example, Derek's relationship with Marti frequently comes off less like they're siblings and more like parent and child.

* FoeYay: Derek and Casey are not exactly straight up enemies, but their antagonism is the strongest in the show. Combined with the occasional, unintentional flirting, it naturally leads to this trope.

** Dasey (Derek/Casey) skyrockets above every pairing each of them ever had in the show, even with Derek's final love interest in the show being his RelationshipUpgrade with Emily and Casey being paired off with Truman (they each also had different love interests in TheMovie too). While never actually intended to be interpreted as romantic through the writing, they were viewed as having such intense BelligerentSexualTension rather than sibling rivalry that they became the very definition of this instead. Even actors Creator/MichaelSeater and Creator/Ashley Leggat strongly support the ship.

** Dasey (Derek/Casey) skyrockets above every pairing each of them ever had in the show, even with Derek's final love interest in the show being his RelationshipUpgrade with Emily and Casey being paired off with Truman (they each also had different love interests in TheMovie too). While never actually intended to be interpreted as romantic through the writing, they were viewed as having such intense BelligerentSexualTension rather than sibling rivalry that they became the very definition of this instead. Even actors Michael Seater and Ashley Leggat strongly support the ship.

** Derek/Casey, to the point where at least 90% of the show's fanfics were centered on them getting together. The actors themselves admitted that even ''they'' wanted to see Derek and Casey end up together.
** [[ToyShip Edwin/Lizzie]] is another.

* WhatDoYouMeanItsForKids: The first season had the characters explicitly talk about breasts; there was an episode focusing on feminism; Casey often accused Derek of being sexist; and Derek made out with [[KissingCousins his step-cousin, Victoria]]. Things like this often made the viewers wonder if the show was directed at kids.
** Then there was the whole [[PeripheryDemographic older audience of the show]] who only watched it for the amusement of seeing two step-siblings fighting their [[{{UST}} sexual attraction to each other]] (WordOfGod insists there wasn't any, but it's rather hard to believe), and who were shocked when Derek and Casey didn't end up together at the end.