When I watch LBT, I see it's obviously clear Ducky cares about Petrie. She kisses him, she comforts him on not being able to fly, she's the only one who actually cries when he seems to be dead, she runs to him and squeezes him, she goes to comfort him in 7, and so on. But does Petrie feel the same way?
My main argument is from watching 7. As we know, Ducky is kidapped. Shortly afterwards, we see the gang on a hillside deciding what to do while the adults argue, and, at 33:14, we see Spike drawing in the dirt and...crying. I was so shocked on seeing this. Spike never cries. He didn't even cry in the original, in which pretty much the rest of the main cast did (with good reason). It's that sudde moment that makes you go, "Oh my god...he really cares about his 'little' sister! Ohh..." and then he immediately sets off to find her.
Petrie on the other hand is a different story. He just bitches about how "this all my fault!!" and doesn't seem nearly as depressed by Ducky's kidnapping. He's not crying, he didn't seem motivated to find her even. Littlefoot seemed motivated, Spike was defiitely motivated, but all we see with Petrie is a motivated grin between him and Cera, which is great, except...it's his "girlfriend" who's been kidapped.
OK, we get to the cave and find her, and guess who's the first to run to her? Not Petrie, but Spike, while the others just meander over. It's a extremely touching moment. The aforementioned crying scene and this pretty much says Spike loves Ducky more then Petrie. OK, so they hug afterwards, and it's a sort of replacement for the cute moment that Spike stole, not as good but OK. He asks her how she got there, she tells her story (which is too short).
And then Petrie ruins this "next-best" moment by breaking down sobbing.
In the earliest films I'd have to say Petrie was actually my favorite, cause he was less annoying, and if it was the Petrie of the earlier films in 7 I'd be quite mad at Spike for stealing a moment which could have been a really nice hommage to the movie 1 incident in which the rest of the gang thinks Petrie is dead, and Ducky runs to him when he comes back. But by 7 Spike was definitely my favorite, ad Petrie was just "the dookie". He completely deserved that moment, whereas Petrie was...well, more annoyig then usual in this one. Clearly Spike's devotion to Ducky as a brother overpowered the beloved Petrie/Ducky shipping in movie 7, but what do you think?
AAd just for the record, if you look real close when Spike runs to Ducky, you can see just the slightest discernable expression of jelousy on Petrie's face.
j/k