Glitch?

Okay guys
This is the second time this has happened to me
Whenever i move a pawn to lets say b4
my opponents pawn will kill my pawn  axb3
Its happened to me twice and ive lost both games
has this happened to anyone else? 

http://www.chess.com/learn-how-to-play-chess.html#special

do you even know what im talking about?

its en passen and it is a real move

Yes, he does.  You're talking about an En Passant capture, and oinquarki provided a link to the rules which talk about it.

In other words, it isn't a glitch.  It's a rule that you don't know about.  A rule which is arguably one of the least known rules, so it isn't any surprise you don't know about it.

Oh my god
How can i not have known that
Anyway sorry for the topic
But this just blew my mind 

Because a thread like this gets posted every other day here.

I'm glad the problem is resolved.

En passant freaked me out the first time I ever encountered it, too, but at least I was playing the computer and then looked up the rule.

I apologize for my rudeness
Thank you :) 

lol no need

It's usually about eighty times worse.

Yeah, what's funny is when you get newbs who insist that there's a computer glitch or else their opponent cheated even after having the rule explained to them.