I am quite aware of this personality trait. My Hubby hasn't figured it out yet. There are many things that I am willing to share: the toothpaste, the remote control, the covers on our bed, and even our car; however, I am not willing to share my FOOD.
If I am eating out or eating at home it makes no difference. I do not share my food. Get Your Own. I don't want to split my meal with you.
So, when the pregnant lady has been craving a Beto's breakfast burrito for 5 days, don't bring it home and expect to "have a few bites." Which really means Split the burrito in two. I WANT IT ALL. GET YOUR OWN.
I don't in any way feel this is selfish. I just knew what I wanted. If you knew you wanted some, you should have gotten some. That was a choice that you made. Food is precious to me. (obviously, I'm getting fatter by the second and it's not ALL baby) Leave my meal alone. Thank you.