I like that you found it sweet. I can certainly see a situation where it would be - basically a recognition that yes you've gone out of your way to show them love, it wasn't a requirement, and it's not necessarily because they're the most lovable person on the planet, but you've done it anyway.
I can also see a different person, maybe saying it with a different tone, meaning something much more arrogant by it. I've known people from whom I wouldn't have found that a sweet response. But just goes to show you that everything is relative, and meaning is determined by context as much by words.
