When you go for weeks being insulted and humiliated, but it doesn't phase you. Then, unexpectedly, you get angry about everything that happened to you previously, and feel like punching something.
Hey, stay away from him, he's having an emotion explosion.
When someone has a sudden outburst of emotions which is usually very high pitched and quick in tempo.
It is normally followed by erratic arm movements and an over-excited grin.
An emotion explosion can be back-fired by 'p**sing on their bonfire'.
Tim: OMG!!! Have you seen pirates of the Caribbean??!! *flails arms wildly*
Cat: 'Yes, it was crap...',
Tim: Oh, I had an emotion explosion again didn't I.