Question:
I remember this one time when my mom and I were at this resturant. She saw the waitress yawn while at the cash register with some customers or something and commented that it was disrespectful. Do you agree? I explained to her that a yawn is just an effort to inhale more air to stay awake (thanks to science class way back when). She just said I was talking back. So here's a smiley depiction of my mom and I over the issue: here's my mom rolling her eyes and here's me rolling my eyes at my mom rolling her eyes

Choices:
Yes
No
Yes and this post made you yawn
No and this post made you yawn
Who cares?

 

When you have to yawn, you have to yawn. It's like farting. You just try to do it discretely (and downwind).

I don't think yawning is disrespectful, but it can be interpreted as such. Also, the rest of your body language can contribute to that. If you're obviously bored and you yawn, you're probably just being rude in general. If you are exhausted, people will see that, as well.
If you are unable to stifle a yawn, I think the best approach is to cover your mouth (no one wants to see your tonsils) and then excuse yourself afterward, just in case anyone is thinking about being offended.

It's not disrespectful, but in front of people, it's nice to cover your mouth.