Rawr. Here be dragons.

Of course it happened. Unfortunately for me, she already found someone else when I was about to ask her. My mind shifted in reverse, still wanting to be friends with that person, but also not wanting to intrude. I think that's the worst part there is to being befriended to the opposite sex. Once they find someone, and you want to spend the same intimate time with them as before(just as friends), you easily can be felt as intrusive.

So yes, it does happen, but if it's only one side.. you're better off by completly stopping with the intamacy and killing of those feelings before things get out of hand. Like causing her to choose sides between you and her BF. And trust me, she'll pick her BF.