A guy who is so blind to see whats in front of him - when a girl is there wanting sexual pleasure - he takes the condom blows it stupidly as if it was a balloon.
"Karl why do you gotta be such a cockballoon bro? That chick wanted the D in the V so bad but you turned it loose you ass-hat !"
The pocket of air that can form over the tip of your penis when you do not put on your condom correctly. A cockballoon can break easily and make wearing a condom pointless.
(verb): The process in which one's scrotum becomes compressed and settles quite near the man's penis (hence the name 'cockballing') due to exposure of one's testes to cold weather, water--preferibly salt water--, and even ice.
"I knew that I would soon be cockballing if spent too much time swimming with the cute sailors." uhhhhhh
"Daily cockballing has become quite the hobby among most male snowboarders and skiiers."