Help! My Characters Are Rebelling!

Aaargh! I so didn't mean for...oh, wait. I might as well warn you that the next things I'm going to say are **SPOILERS!!** and you shouldn't read them if you would rather be surprised when my books get published. When, not if. =)

Okay. So, the two characters that are bugging me are Arimathea and Abriel.

Arimathea

age: 14
height:5'5"
build: On the slimmer side, although not quite wispy.
Personality qualities in brief: Forgiving, optimistic, content, unshaken, trustful.
Personality faults in brief : Forgetful, tends to overlook other's faults so much that she would trust a traitor.
Brief Bio: Raised as an orphan in Draelaet, she comes along on the quest to close the portal and proves to be an invaluable member of the group. A follower of Light.

Abriel

age: around 16
height: 5'11"
build: fairly average, okay for athleticism but not excelling athletically.
personality qualities in brief: Sensitive, protective of loved ones, strong leadership and organizational skills.
personality faults in brief: Able to detach himself emotionally, selfish.
Brief Bio: No one knows very much about him, but he claimed falsely to be a prophet and tried to lead his traveling companions into traps to accomplish tasks given to him by Dark.

And this is my problem.

You see, Abriel was supposed to marry Skye (one of my other characters) and Thea was either going to remain single or marry Erri (another character). But...

...Abriel and Thea are falling in love! I wrote a scene of dialogue between them and they matched perfectly. Just awesome. But...aargh.

I suppose this is a good sign, that my characters are real to me and that I can't force them what to do. If I could, that would mean my characters are weak. But still.

Why. Must. They. Be. Like. That?

Sigh.

Romance in books?

Is it just me, but is romance SO hard to write!? In Sarea it actually hasn't turned out to be that bad, but it was really, really hard. And it's difficult to find good examples of romance in books these days.

In The Inheritance Series, Eragon basically falls head over heels in love with Arya (or at least it seemed that way to me!). That was fine with me...but I don't want to have it like that in my books. I like romance that is gradually introduced, as long as it's introduced well. Roran and Katrina's romance...was, ah, disgusting. It would be great if I wasn't (weren't?) a Christian, but I am, and the fact that Katrina was going to have a baby before she and Roran got married doesn't sit well with me. It's nice that Roran was willing to go basically to the ends of the earth for her, though.

The Redwall Series has really good romance. No kissing and all that; it's more knight and lady sort of thing. Reading those has helped me a lot.

Although I do have a problem yet unsolved in my book: two of my characters (I won't tell you who because that would be considered a spoiler =) are supposed to fall in love and get married. I was at first going to have it that the young man (for the sake of a name I'll call him...Bob) was supposed to rescue the lady (I'll call her Lulu!) from a dire predicament, but then I realized Bob is so polite and gentlemanly that he'd rescue any damsel in distress and not just Lulu. So does anyone have any suggestions for me? I already used the 'get into an argument and then realize they realize that they care about each other' thing.

Thanks!