A term used to describe a girl during that special time of the month, when the partner performs oral ingesting the egg that is ejected through her natural process.
An Egg McMustache (a term built around the Egg McMuffin) is a fun thing to order at McDonald's to go with a two-piece Chicken McNutsack which is a term built around the famous Chicken McNuggets.
"These people didn't hear my order correctly. I ordered an Egg McMustache and they gave me an Egg McMuffin instead. They told me that eggs don't even have mustaches. No, but mustaches have eggs. Where do you think baby mustaches come from? I want a refund!"
When having doggy stylesex with a woman and you decide to have breakfast also. You then crack and egg in her cooch and add your sausage to complete the breakfast delight.
Tyler, while fucking Drew's mom, began to get a rumbling in his stomach. He then proceeded to make a sausage and egg mcmuffin in her snatch, she already had the extra cheese.