Beer & a mustache

I'm writing this quickly before I forget...

Zach and I were just driving home from our weekly BBQ with friends, listening to the cd from his music class. The song that was playing is in Spanish, and one we've only sung once in class. After we talked about the fact that the song was in Spanish and was about animal noises, this is what Zach said:

I sung this song once.

Me: You did? When?

Zach: When I had a beer.

Me: What? A beer? When you had a beer???

Zach: Yes, when I had a beer and a mustache.

What??? Where does he get this stuff?? I realized as I was writing this that he may have said "beard," not beer, but still!!! I have to wonder.