A lot of people throw up on a Firday or Sat. night.

Who knows, maybe you're allergic to beer? There are people out there who are, maybe you are too?

Who knows, but barfing after 2 beers is not due to excess, so I'm guessing your body is allergic to something in the brew. Possibly the yeast, or hops perhaps. Either way, don't drink it again until you know for sure.

Or yeah, maybe it was something you ate. A lot of junk food, like fatty, oily foods like chips, or deep fried foods like fries or wings, with the mix of beer, can make one feel very queezy.