Fangry is a portmanteau of "fake" and "angry" which describes a faked or staged anger in order to get ones way. It is used as an escalation of a discussion or argument in an attempt to end it.
"My friend tried to back out of helping me move till I got fangry with them and reminded them all I did for them..."
When you get so angry your asshole explodes fart juices in a deadly manner.
Do that one more time I'm gonna get fangry.