A shortened form of "bloated ego"; used to describe a person who is not conceited or egotistical by nature but becomes this way due a circumstantial or lucky event which happens in his or her life. The person is led to believe that because of this event, he or she is better or more elite than his or her friends, family, etc. This is NOT applied to people who have outgoing yet somewhat self-centered personalities, as these people can often be fun or at least amusing to their friends.
Hey man, that guy seemed like a real blego.
Nah, he's always like that. He's just a little self-centered.
Guys, I'm having a party this weekend!
Sweet, can I go?
No way, only people with girlfriends as hot as mine can go.
Ugh, you've been such a blego since she decided to sleep with you.