Irish Car Bomb

I am only posting this because my mom asked...
An Irish car bomb (that is its full, probably not PC, title) is a half shot of Jameson's (Irish) whiskey, half shot of Bailey's (Irish) cream, which you drop into half a pint of Guiness (Irish beer) and drink in one gulp. It needs to be served pretty quickly after it's been poured because the Bailey's will curdle if it sits too long...