Like the game of regular chicken but slightly sexual.
Two people (same-sex or opposite sex) who are usually just friends flirt, make gestures, and make physical contact with each other. Each comment, gesture and touch more sexual than the last. And who ever gets creeped out first and calls quits, loses.
Jack: I like your eyes *brushes hair out of face*
Jane: I like your butt.
Jack: Touch it then..
Jane: Fine, I will.. *approaches butt with hand* ... No!! I can't! I quit!!
Jack: Yes!!! I win!! I'm the master of sexual chicken! By the way.. you owe me lunch tomorrow.
Sexual Sun is an emoji with the looks of a sun. Whenever someone sends someone else the Sexual Sun emoji three times, sexy things will happen to the receiver of the emoji message, which would be Sexual Sun having repetitive sex with the victim. The Sexual Sun also likes to sing "I Wanna Sex You Up".