Cat's expression, to her credit, did not change dramatically - but it did change. Her eyebrows rose, her lips parted just slightly, taking a moment to absorb this revelation, then considering what it meant. It wasn't a great surprise to hear, though not in so many words, that Charlie was not the greatest fan of intimacy, but it was difficult to make it into one's - mid-twenties? - without having been in a relationship. Cat had a few guesses as to why, and part of her - a large part of her - wanted to take the girl under her wing and make her understand safety, make her understand being cared for was not necessarily impermanent, or bad even if it was.
But that would be saying too much, presuming too much, and so instead she simply moved next to Charlie. Their arms could have brushed, but they didn't.
"Well, it sounds as though it'd take someone pretty special to earn a relationship with you," Cat said, looking at Charlie. "But when you think about it, you've probably had at least a few, even if they're not what you think of that way. We have a friendship; that's a relationship. And it sounds as though you and Rylee have a close relationship, even if it's not romantic." She smiled at her. "Romantic relationships aren't so different than friendships, when they're good. There's just more sex, which is rarely a bad thing."