So, what kind of relationship do you have with your partner? If you're in a long term relationship, you're probably used to them, but they should still give you butterflies, and the other way around, of course. Sounds impossible? Not really.
We each have our own ideal of beauty and we each know, what are the things that attract us. Sometimes it's just a look, other times it's the way they speak, or their hands, perhaps the shape of their nose, or the attention they pay to us.