Someone who is very pale because during the summer months, they spend all of their time inside, usually in front of a television or computer monitor instead of enjoying themselves in the sun like everyone else. Everyone else darkens out in the sun, while said insider will stay pale because their only form of light is from a screen.
I cant believe Mike won't come to the beach with us! He said he'd rather stay at home and work on his monitor tan. What a loser.