I've bought those items for dw on occasion. Heck, I even bought some once for a female friend who was in dire need, and her boyfriend was too embarrassed to do it.
There isn't a lot of explanation required, just get whatever she asks for.
Between me growing up with a sister, having mostly female friends, and then dating my wife who has 2 sisters and an outspoken mother, this stuff was always talked about. No big deal to me.