A Tesch can mean
1. Your cock/penis/schlong/wang/whatever the cool kids call it nowadays
2. A wierd/but sorta cool dude
"Man, He's so hot, i bet i can get some of thatTesch by the end of the night"
"May i lick your Tesch"
"Man he's cool, but he's such a Tesch"
"What a Tesch"