Sure, Abel can take his time and drag this out, frustrating Cain to the point where he leaves, but what would be the point in that? Cain would then ignore Abel in return and their training would go to shit.

He doesn't watch Abel get changed this time because he's too busy looking for his car keys. Another thing he's just not used to anymore and he drops them down randomly like an idiot.

He curses up a storm along the way, then stalks back to Abel. "Have you seen my keys anywhere?"