She wanted to slug him for teasing her at a time like this, so she did.
Clark:

It is a friendly slug.
Lois: You won't say that after a few more.
“Ow! Ow! Ow! Not the shoulder,” he requested.
Lois: Hah, I was right.
Clark: You only slugged me once.
Lois: So clearly you would not say "friendly slug" after a second one.
“Other shoulder,” he murmured.
Clark:

I still figured a way to get her to touch me more.

She is still touching me.
