I think an added challenge to this should be that she CAN'T see the body part in question (the chest, for example). It has to be a piece of clothing on Superman that ties him and Clark together.

CLARK: No. I'm just worried I'm a jinx.
JONATHAN: A jinx?
CLARK: Yeah. Let's face it, ever since she's known me, Lois's been kidnapped, frozen, pushed off buildings, almost stabbed, poisoned, buried alive and who knows what else, and it's all because of me.
-"Contact" (You're not her jinx, you're her blessing.)