No I can't put that aside for you.

It's one of those requests that seem perfectly reasonable if you're not lying. "Would you mind putting this behind the counter for me and I'll be back to buy it in a short time, I just need to go get a bag/talk finances with my partner/fetch my wallet/park my car a little closer/etc" is very reasonable, that's good customer service.

The problem is that customers lie. I've made the mistake before of putting things aside and they literally never come back to buy the thing. And it's usually something in short supply, so while I'm holding this item from the general public our online inventory claims we have it, because we DO have it, which means people come looking for it because we have it, and I can't sell it to them because I promised that other customer. And the reviews get terrible if we keep promising to hold something and then just don't do it.

The store policy is to not hold items. We do have a click-and-collect system where you can reserve an item on the website and we'll put it aside for you, under your name, with a date saying how long we should hold it, AND the system takes it out of the inventory so other customers don't come looking. So we tell customers to do that, and they never do. Probably because they weren't actually intending to commit to this they just wanted to have the option.

And even though this has been store policy since I started, I admit I still do it sometimes just because the customer kicks up such a fuss. "I literally just need to (any of the things above), you seriously can't put it aside for two minutes?" and stuff like that. Then demanding to know why. Then arguing when I say because customers usually don't come back for it, because they are obviously going to come back for it. When I say it's store policy they want the manager, but the manager doesn't work evenings and I do. "It's TWO SECONDS, come on!"

And every now and then I get a customer who ends at "look, I'm putting it here. I'm coming back for it." and they just leave it on the counter. Then I put it back. And on rare occasion they do in fact return looking for it (usually the next day, though) and either get mad at me for not holding it, OR lie to my coworkers and tell them I promised to hold it.

JUST BUY THE ITEM WHEN IT'S CONVENIENT FOR YOU TO BUY THE ITEM.