secretly having a dark past; having a guilty conscience
shin guards; shin pads; greaves; leggings
to depend on one's parents' (financial) support; (lit.) to gnaw at one's parents' shins
sponging off one's parents
to depend on someone else's (financial) support (usu. one's parents'); (lit.) to gnaw on (someone's) shin
sponger (e.g. off one's parents); hanger-on; freeloader; leech; (lit.) shin gnawer