The Walk

I didn't get the impression that the song is about a man and a woman who are good friends and slowly getting into a relationship. Instead, I took it to be about a woman who's built up quite a few "emotional barriers" for the protection of her emotions, and she's met someone who she's starting to develop romantic feelings for, and she's afraid because she doesn't want to risk getting hurt.

"It’s not safe in here I feel a weakness coming on"

They've reached a point in their relationship where she doesn't feel safe around him any more, not because of what he's doing, but because she can tell that she's not going to be able to keep him at a safe distance anymore.

"Oh, I was doing so well Could we just be friends? I feel a weakness coming on"

Again, she's felt that her method of dealing with the world has worked for her, and wants to keep up with it. So, hoping that she can just ignore her feelings, she offers friendship. And then we have the repetition of the line about her weakness.

And then the chorus:

"It's not meant to be like this Not what I planned at all I don't want to feel like this, yeah No, it's not meant to be like this Not what I planned at all I don't want to feel like this So that makes it all your fault"

Where she talks about how she hadn't planned this, how she's confused and upset because she doesn't want this to happen, she doesn't want to end up caring for someone else. And then she blames the man, because she wouldn't have reached out for emotional contact herself.

Then the lines:

"Big trouble Losing control Primary resistance at a critical low"

and

"They've got control There's no way out We are surrounded"

Both talk about losing control (losing it to someone else) and the breaking down of her resistance.

Finally, with the lines:

"Give in, give in And relish every minute of it"

It seems to me that she comes to terms with the feelings she has for him, and more or less makes up her mind that she'll give into it, because the rewards are greater than the consequences.