She: I may be small, but I can beat you up
He: Um, yeah…sure you can…
She: What??? I have totally kicked your ass before!
He: I’m going to let you in on a little secret…I let you think you can beat me up, because I know you let me think I’m as smart as you.
She thinks this over for a second and grins, realizing that He does have his occasional moments of genius and then punches him (affectionally) on the arm.