Lana: It's strange. All this time, I thought Lex never even liked Whitney, and then he goes and arranges all this.

Clark: I think Lex feels he's become part of our lives.

Lana: I'd like to believe that. You asked him, didn't you?

Clark: Being friends with Lex Luthor can be complicated,
but it has advantages. (After he says that Lana kisses him.) What was that for?

Lana: Just being you.
She says she kissed him because he was himself and did all that for Whitney?
Because he's a nice guy, I guess.
Grammar GeekBecause he's a nice guy, I guess.

So she just omitted 'for' ([For] just being you)?