https://www.vice.com/en_us/article/y3gkbw/erotic-scented-face-masks-fetish-item

Masks are a critical and effective protection measure to help us get through this pandemic, but there's no denying that they are annoying as hell. They prevent us from seeing the faces of strangers and friends. They cause maskne. They fog up our glasses. But to a select few, they are also an object of desire.

If you see someone wearing a mask who seems particularly delighted, it might be because they paid for the pleasure of wearing a mask that smells like someone else's genitals or feet.