History Heartwarming / PhineasAndFerbTheMovieAcrossThe2ndDimension

** [[DoubleSubvertedTrope Until]] [[Recap/PhineasAndFerbNightOfLivingPharmacists a few]] [[WesternAnimation/PhineasAndFerbCandaceAgainstTheUniverse other episodes]] and [[WesternAnimation/MiloMurphysLaw a spin-off show]] came.

* Before going to find Doofenshmirtz-2, Perry pulls off a tag and hands it to Phineas. [[spoiler: Said tag turns out to be a locket...which, when opened, fits perfectly into a keyhole that grants the boys access to copies of all their inventions, and a pre-recorded message saying that Perry always trusted the boys and knows they're the only ones who could ever help him if he needed it. Best part? The locket contains three pictures: Perry, Phineas, and Ferb.]]

* When Phineas and Ferb learn that [[spoiler:Perry had been keeping duplicates of their inventions in case he ever needed their help, and Phineas realizes that Perry trusted them]].
** Not to mention [[spoiler: Perry's look of pure joy upon seeing that Phineas and Ferb got his message and have indeed come to help out.]]

* When Phineas-1 and Ferb-1 first meet Phineas-2 and Ferb-2, Phineas-2 is overjoyed to see Perry. He thinks it's ''their'' Perry, who's been missing for a long time. When Phineas-1 tells him it's actually Perry from their universe, Phineas-2 asks if he can hold him for a little longer anyway. ''Both Ferbs start [[NotSoStoic tearing up]].''

* Phineas's speech to Perry at the end of the movie about how he now and always will consider Perry to be a great pet and a great friend.
* The deleted scenes have a longer version of the scene where [[spoiler:Phineas and Ferb discover their scanned inventions]]. At the end of the scene, Phineas is delighted to realize that [[spoiler:Perry saw all their activities after all!]]

--> '''Phineas''': Now ''thats'' the way to start the day!

* When Phineas-1 and Ferb-1 fail to receive any help from Phineas-2 and Ferb-2, Phineas-1 suggests they go seek Isabella-2. In their dimension, Isabella-1 isn't as smart as Phineas-1 and Ferb-1. Baljeet-1 is. This shows that if there is any one of his friends Phineas-1 trusts the most, It is Isabella and that Phineas trusts Isabella's problem solving more than Baljeet's.

* When Doof-2 announces that Perry has been caught, Phineas's ''almost immediate'' reaction is to declare that they must go save the platypus, despite the risk it may cost them the chance to get home as pointed out by Baljeet-2. Even after their falling-out earlier, Phineas is not willing to give up on Perry entirely.

'''Phineas''': (angrily) We're not going anywhere without our platypus!\\

* It would be surprising if you didn't see it coming a mile away, but it's notable that, after 2nd Dimension Doof has had Platyborg [[spoiler: attack Perry (in pet mode) to make him reveal himself as a secret agent]] [[note]]which is rather adorable in and of itself, since the boys immediately rush over and fuss over him[[/note]], he alters the plan and has the robot [[spoiler: attack the boys]] instead. Perry's reaction is immediate.

*** Taking this a step further, the song "Missing My Nemesis" in "It's About Time", sung from [[FriendlyEnemy Perry]]'s point of view, also addresses Doof as Dr. D. showing that Perry does see Doofenshmirtz as a friend.