I think this is less "love at first sight" and more "a relationship beginning to blossom". When Garnet said that line, she was talking to a man who had taken one look at her and declared "I am in love with this woman" without a second though. Here, however, both of them are probably less "in love" with each other than they are just amazed at what both of them had went through, and now they are finding that they enjoy the other's company.

Well, if you wanna get technical, this isn't the first time they've met. Their love wasn't a result of meeting; it was more or less a result of Ruby causing the accidental fusion.
Really, I don't think you can love someone just from seeing them. You have to know them in order to truly love them. Sure, seeing them might get you interested – in fact that's more than likely the case – but "love at first sight" is, while a sweet thought, not really possible.
But that's just my take on things. Don't let my piss affect the taste of your cereal.