Not sure if I would ever write this myself - already got Vendetta and too many other story ideas on my plate as it is and also don't have more than a few plot threads for this idea, not really enough to string a full fanfic out of it. Plus this feels might be better in a comic format (and I don't have enough artist skills to being able to draw often consistently for that either 😅).
When visiting Wendolene's shop to pick up some wool, Wendolene pulls Wallace and Gromit aside because she's noticing signs that Preston is acting sentient again and is worried about him possibly switching back to evil.
Wallace, of course, besides seeing Preston is switching between bipedal and quadrupedal poses (I'm assuming Preston can switch out his wheels for hands) and that he's starting wearing a knitted jumper (the one the knit-o-matic made out of his fur) over his metallic skin, doesn't think there's anything odd. But Gromit, however, is on high alert and decides to keep a close watch on him
And this ends up with Gromit spending more and more time with Preston to keep an eye on him (magnet close at hand, just in case). However it seems that Preston while indeed getting back his sentience, is more simple and sweet than evil, with perhaps just a touch of extreme protectiveness at times for those he cares for (Gromit falling quickly under that bracket from the amount of time he's spent with him over the course of the story)...and Gromit soon finds himself... falling for him?
Cue a former-enemies-to-lovers storyline, Gromit having an existential crisis over falling in love with a robot (and a robot that, while not created by, has been tampered with by Wallace, to add on top of that), Wallace being his usual oblivious self but ultimately supportive when he finds out, Wendolene cheering them on in the background (because if her dog is getting together with anyone, then Gromit, to her, would be the best match) and Preston slowly learning how to love and be more than just a once-evil-cyber-dog.
And throw in added conflict when Shaun learns about this and Bitzer having to deal with an enraged sheep going full out to prove that Preston must be still secretly evil and pulling the wool over everyone's, especially Gromit's, eyes (pun only partially intended 😂), all the while said sheep keeps angrily insisting to him that, no, he's not still traumatised and reacting this way because of said trauma.
(In this, Gromit and Fluffles would've broken up amicably a while beforehand, Fluffles going off to university and to have a chance to find herself outside the whole Piella-debacle, and the two deciding not to do long-distance).
Either this is a really fun idea or I just really need to go to bed so I can go back to focusing on Vendetta and things 😂😂😂.