He reahes up to a shelf, and removes a green crystaline cylander, which viewers who have been paying attention will instantly realize is composed of kryptonite. He handles it a bit, before continuing his exposition
Here's what, in my pure and perfect world, would have followed:
Lex: "Do you know what this is, Ms. Lane? This... is a kryptonite condom, by means of which I mean to screw the Man of Steel like he's never been screwed before.
He pauses, looking ascance at Lois, raising an eyebrow.
"Not literally, of course. I assure you, Ms. Lane, I'm all about the clam. No, I mean metaphorically. Nevertheless, if my five years in prison taught me nothing else... it taught me the value of making another man my bitch".
He lowers the cylander to his broin and absent-mindedly strokes his hand up and down its length, seemingly unaware that anyone is even watching.
Lois covers her son's eyes with one hand.