Sparkling Egg Nog

My grandpa was kind of quirky (aren't all grandpas?). He had several of his own concoctions that I still enjoy. One of my favorite is adding ginger ale to egg nog. It's quite delightful, and I much prefer sparkling egg nog than plain.

Here's how to do it - the method is important:
Fill a glass a little less than halfway with ginger ale, then fill the rest of the glass with egg nog.