What is Icecap?
1.
the cum that comes out on top of your poop after you have had anal.
The morning after Corey blew his load in my butt, the tip of my poop had an icecap.
See
2.
A guy who betrays you. Someone who tells you and shows you a person who they are only 20% of, while they hide the rest of their negative personality traits, much like iceburgs but iceburgs have more depth.
Icecap secures his girlfriend's trust, but one day his girlfriend finds out he is not what she thinks he is, icecap ends up alone with noone but his ign buddies and some naked girls he finds on porn sites.