I am the only one of my coworkers wearing a mask. Half of the Latino student population is absent (Latino parents make up a really disproportionate number of calls from parents concerned about Covid). I’ve seen a couple kids wear them in and take them off once they realized they were the only one.
Welcome to the new normal
If you can't switch, this could help? Low cost but very effective DIY air filter. Wearing a mask in your living space isn't practical, but this could passively reduce the risk somewhat - and at the very least minimize the viral load you receive if (when) he does get infected.