The word "sheck" is a combination of the words "shart" and "check".
Person 1: "Is Jerry taking a piss or a dump? What's taking him so long?!"
Person 2: "Nah man. He is just shecking."
dude2. man your being a total sheck right now
dude1. you have so easy being poor
dude2. your a fuckin fagget sheck
Kelli: This idiot missed my neck and gave me a hickey on my sheck, girl !
Taylor: DANG girl. He's a boof/gweet.
Kelli: Oh girl i know.