I really sympathize with you. In the AvP comic, which started the whole series (off right) Dachande and Machiko develop the same relationship, but the situation is handled MUCH better. They basically save the Pred's life, and all of his young yautja are let loose on the colony and start killing everything. Machiko then saves the Pred's life, and the situation escalates.
I feel that in AvP the movie it's just handled terribly, same with the stares and unbearable moments meant to get an "ooh" or chuckle from the audience, like when Scar turns to watch Lex leave after she shoots Sebastian. Any mature director would go "no, no no no, no way, that would be ridiculous and completely out of place with the Predator character." Not our friend Anderson
.
So many scenes were like that, just the little things that push the movie into the B category. The general behavior of the Preds and Aliens flips from almost accurate (including using the same growls and screams from the old movies) to totally bogus, where the Preds act like huge, clumsy football players, not the cunning, agile, and sadistic killers they are, and the aliens hop around like cats and do idiotic things like leap on spears and shriek before they attack so you know they're there. They became stupid movie monsters, even when the Aliens are communicating with their queen, they like turn and stare at the wall. These things illustrate that the movie was made for someone who had no idea what an Alien or Predator are, and most of these people (if they can get over the acting) probably like the movie because they don't know how poorly the creatures have been represented.
I think the Celtic/Grid fight is actually one of my favorite scenes, but they STILL manage to throw in total goof things, like when Celtic jumps up off the ground... he looks like the stay-puffed marshmallow man! Just awkward, same with Grid. He will act like an alien, then act like a damn shrieking housecat. What gives? It's this constant back-and-forth that drives me totally insane about the movie.
I still own it, however, and for some reason still watch it. I am weak, the movies take advantage of me. I'll deal with their crap just to see the few scenes of awesomeness.