Gifts between girlfriends...

Without getting into any specific details, would it be appropriate for girlfriends to give gifts of undergarments (silky thong under garments) to each other as birthday gifts? Not including wedding parties, how many of our female participants have purchased undergarments for their girlfriends?

I'm not asking for some perverted thrill but only because its a real scenario in my relationship with my wife. Our marriage has became increasingly different and almost odd at times. I have one other female friend say, that it's very wired and that she would and never has, just bought such a gift for any of her girlfriends. If I'm out in left field, I want to know! I love my wife and I'm embarrassed for even asking such a question. But on the other hand I need to know if I should be concerned!

Please let me know the gifts between your girlfriends.