Is It Proper For A Wife To Wear A 'g-string'? Please Help - Family

I love my wife and I always give her freedom to do whatever that will give her joy. But some days ago, she came home with a G-STRING ladies underwear saying it good for her HEALTH. Though I have not concluded whether she should wear it or not cox i believe it is unholy and improper for a married woman.

Please house, should i grant such request?