I’m going to offer a different perspective here. I have a boyfriend who I care about soooo much. Idk if I would call him handsome or sexy though. Not in the traditional way. Not what we see in media and are kind of conditioned to describe as handsome or sexy. I just find him irresistibly cute. I just want to cuddle his freakin head off. And there are things that he does that are sexy to me… but it’s complicated. It is possible that she feels this way about you. This is how I feel about most of my boyfriends. I find them very attractive but those words don’t usually work for me. And when we’re alone, yes they are very sexy to me.

Hope this helps! I’m just one person. But I’m getting the feeling your gf might be misunderstood but only you can know that.