Decorum? Tommy doesn't know the meaning of the word. (Yet another one that he actually, really doesn't know.)

But for some reason he thought there'd be a saddle and bridle involved. And when there isn't, he stares with uncertainty for a moment at her outstretched hand, and the broad back that he's supposed to 'hop on.'

He ain't no scaredy-cat, though.

He grits his teeth with determination, and grabbing her hand and vaulting off the bench, he swings a leg over the horse's back. He lands with an oof behind her, unused to sitting like this, and so high up. He also finds himself clinging to Kate's middle to keep from sliding off. Cooties and decorum be damned.