Yeah, but Steve is holding out for commitment. Not just a swept-away-by-passion-one-night-stand in the humid jungles of the Savage Land, et cetera. He's all, I am not taking you roughly on these furs while T-Rexes roar in the distance and the night air - are you listening? And Tony is SORRY I kind of zoned out after the bit about taking me roughly.

The sabre-toothed tiger episode is a masterstroke of Steve's. After the bear incident, he observed Tony's glazed eyes and decided it needed to be done again, with more danger. So, sabre-toothed tiger. Then, he insists they adopt the adorable cub, and cuddles it while Tony stares fixedly and wonders what the hell has happened to his life.