Yawning is good for you; it stretches your eardrums and the muscles of your jaw. Since you can’t help it anyway, you might as well get credit for it and consider it a blessing when your yawning makes people around you yawn and when you cannot help yawning because you see someone else doing it.
On a bus, waiting in line at a bank, yawning is one thing that you can share safely with strangers of all ages and genders. Yawning is an empathetic reflex, and strengthens bonds in social groups, although non-empathizing researchers may not agree.
In an audience, in a meeting, or one-on-one when you’d rather be fishing, everyone notices when you yawn. Intentional yawning is a political act; it can be a social commentary, a personal plea, and it can give you needed personal space. Go ahead. Pandiculate dramatically; people should give you the benefit of the doubt and should not suspect that it’s deliberate. But refrain from yawning before a judge or at least try to make as little noise as possible or you may be swiftly found in contempt of court.
We cover our mouths to deprive an evil wandering spirit or plague bacterium of an open door into our bodily temple, ignoring the fact that our bodies are already swarming with bacteria and spirits. But yawn because you can’t help it, and then make the sign of the cross, and apologize to whomever you may have exposed.