A weeknighter is a girl/guy you only hook up with during the week when your friends are not around so you wont have to face the epic amount of shame, humiliation and torture they will make sure you feel.
I can't call him to come out- it's friday.. he's a weeknighter.
A cod player who doesn’t hit his shots or do anything for the team other than being a target for the enemy (when he’s not hiding in a corner) or dying at the start.
When a hot girl is within a viewing angle where you can see her but she can't see you so you can have a wank.
Chris: Hey Dave, what the fuck are you doing.
Dave: Shhhh, I'm within wanksight of your wife, leave me alone Chris: Get out of the way and give me a go ya sneeky coont