Can a mask be worn as underwear?

No, you can come up with this idea. It can be said that your brain hole is also very big. I'll list the reasons why you can't.

1. Masks and underwear are completely different in size and coverage. They cover different areas, so they cannot be used as underwear.

2. The air permeability is completely different. Usually when wearing a mask, I will feel that my breathing will be weak and stuffy. If used as underwear, the air permeability is not good, and private parts are prone to some diseases due to insufficient air permeability.

3. The design of the mask is completely different from underwear. One is the face and the other is the private parts. It can be said that there is no accommodation at all, so the mask can't be worn as underwear.