A Game of Pretend
A game of pretend is a meme (usually) involving two males, where one male often (but not always) tricks or seduces another male by dressing up as their love interest and convincing the other party to pretend with them. After preying on their ronery insecurities, and their lust for a particular character, they will have gay sex. Afterwards one party will usually have regrets, worrying about their sexuality, while the other usually wants to continue the "game of pretend".
The original meme involved Konata from the Lucky Star anime, but there are now variations on it for many different settings.