Ask to have it.

"So, can I use it for awhile then? I did help you."

"Hm..." Joivus taps his chin. "That does make sense, but I did my share too. How about this, John. You keep it for a week, and then I'll keep it for a week, and we'll switch back and forth. That sounds fair, right?"

You shrug. "Fair enough. Sure. But I get week number one."

"Fine, fine! I can wait. You drive a hard bargain. One week from day, and it's my turn. Thanks again for the help, though. I couldn't have snuck in there on my own."

"Not a problem, Joivus."

He hands you the cube and you hold it in your hand.

The two of you depart. He wanders off, and you drive back to your house. It's incredibly late now. You're tired, it's incredibly dark, and it's been a long day. You step inside and immediately walk to your bedroom to pass out for a nice sleep. Hopefully.