I don't get why he's This upset?

This guy and I were talking and flirty with each other. Well lots of ppl knew I liked him but I started hearing things like he didn't like me the same though he though I was cute and enjoyed the attention. He told me he liked me though. Well later he found out about this lie I told him and now he is really angry and someone that I was once really close to know acts like I have the cooties! I'm thinking he cared more than he thought or showed otherwise why is he soo upset?!