Is it "perving and wierd" for me to like seeing my girlfriend of the last 6 months in lingerie occasionally?

We've both in our early 20's, we have great sex constantly, she's not a prude, and we've been dating for almost 7 months now, and she still says its creepy for me to look at her when she's in her underwear. She buys a lot of it, ranging from basic lacy bras and thong sets, to leopard print crotchless panties, has no qualms about wearing it clubbing, to university, or just wandering around the house, yet anytime I ask her to wear it for me, or tell her it looks nice, she says no, and tells me I'm creepy, and a pervert. I'm just wondering if my actions are in anyway wierd, creepy, or pervy, or if they're just normal.