This is not only alluring on principle, but they'll see if he breaks something. Stress testing.

It's fine.

Bruce does not go effortlessly. For a while he can push up, keeping Clark suspended in a battle between gravity and his own strength, but the angle makes him concede or strain past good sense. Clark will have to work to get his wrists against the ground, though, and Bruce shifts one knee like he's threatening to throw him. Doesn't follow through. Yet.

"It can be satisfying," he says, breath a little thin from strain, "pushing so hard it burns."

Definitely a concept they know about, intimately, in themselves and each other; he's verbalizing purely to watch Clark's eyes as he listens.