Sharing Masks? Should It Be Done?

Wow. Here is some food for thought: my family doesn't get out much except for a grocery run every now and then, to pick up food, etc... the same as many of you. We have our masks on hand just like everyone else. I mentioned to a friend of mine the other day, that we just 'grab a mask and go' without really paying attention to who gets what.

Her response is that we should NOT be sharing masks! I said, we are family, does it really matter? If I send my teen in to the store to grab me a couple of things, I just hand him a mask from my vehicle, who knows who wore it before? As long as he's wearing one, I don't see a problem? Thoughts? Do you think it matters if people in the same household are using the same masks?