Jealousy

[Lorenzo]

Beware of jealousy,
It is the green-eyed monster which doth mock
The meat it feeds on.

-Shakespeare

[Lorenzo]

Yet there is one more cursed than them all,
that canker-worm, that monster, jealousy,
which eats the heart and feeds upon the gall,
turning all love's delight to misery,
through fear of losing his felicity.
Ah, gods! that ever ye that monster placed
In gentle love, that all his joys defaced!

-Spenser