Insulted, or flattered?

I was just picking up some snacks at the store, for my grave shift. I was standing in line. This man is standing on the side, yacking to himself.
Thinking he's a random crazy dude, I just ignore him.

When I approach the cashier, he comes up to me and leans in my ear and whispers: "You have the most perfect ass I've seen all week! I  hope you don't mind me being so blunt..."

I just smiled and said thank you.

I pictured a sophisticated lady getting all huffy and puffy about it. But, I wasn't flattered in a way that made me feel sexual...but more like, it's a nice gesture to be told I  have a nice ass??

I did find it hilarious, so, I think that I will just stick with that. hahaha!