My finger hovers over the image of 'loose onions'. Could I get away with it? Avocados are pretty expensive. My heartbeat rises and I peer out of the corner of my eye at the security guard by the door.
"Please insert your card into the chip and PIN device."
I couldn't do it. My finger pressed avocado, I weighed the onions properly and inserted my debit card.
A similar moral conundrum might well have concerned Nicolas Long, the 25-year-old City recruitment consultant who was found guilty of stealing up to £450 worth of groceries by scanning all his fruit and vegetables as "loose onions" and sentenced to 180 hours community service.
Or at least the first time he did it it might have done. Mr Long managed to get away with it 20 times before he was finally caught.
Having never stolen from a shop, it was a pretty nerve racking experience for me even considering it. But I can understand some might enjoy the adrenaline rush and how those on low incomes might be forced into it to feed their families.
From what I hear, Mr Long is far from alone in his crime -- he was just unlucky enough to get caught.
Tom,* a 30-year-old young professional living in Stoke Newington, London, told me about his experience with Sainsbury's self-service tills.
He said a few years ago his friend, a student at Goldsmiths College in her mid-twenties at the time, would scan her Sainsbury's shopping through as carrots.
"We'd normally go to the self checkout because no one bothered to check anything, so she just put everything under the carrot code," he said. "She pressed the code for carrot, weighed them, then she'd get a long receipt of carrots and pay for carrots for everything."
He added: "As far as I know she doesn't even eat carrots."
Tom also confessed to stealing from a supermarket himself.
One day at a busy Tesco in Hackney he waited to be served for a long time but couldn't get the attention of any staff members.
"I couldn't get any service," he said. "I was busy and frustrated. I couldn't get help. I said, 'Can I speak to someone?'"
Still no one helped him and he decided to simply walk out of the store with his unpaid for groceries.
"I wanted to do something extreme so I could get some attention and speak to someone, but even doing that no one cared in the store," he said.
Tom got away scot-free and told me he did not feel guilty about it, though said he would not do it again.
"I don't feel guilty at all," he said. "I was trying to get caught so someone would come to see me regarding my shopping, but my ultimate goal was to get my shopping done, so if that was an easy way to do the shopping...then obviously I'll go for the quickest way."
He added that multinational Tesco being "rich" also contributed to his not feeling guilty.
"I would never steal from a local shop," he said. "They need to be supported."
He believes this kind of theft is common in his area.
"People are poor in Hackney," he said. "What do you expect poor people to do if they haven't got money?"
Judging by Twitter, the the practice of conning self service tills appears to be popular.
A Sainsbury's employee told me, however, that the machines should be "foolproof".
"I don't know how they can get away with it because the machine shows the weight of the item when you put it down," he said. "The people who make the machines say they are foolproof because it has a weight for every item.
"If there is a variation [in weight] it says 'unexpected item' and the cashier goes across and checks it. So even though people may try because there is [only] one member of staff on six tills, they shouldn't theoretically be able to because the staff member checks the bags."
I wonder if Sainsbury's will be clamping down on this? It seems to me more likely though that the money saved by not having to employ as many staff on self service tills probably outweighs the loss from the occasional illegally discounted avocado.
*Name has been changed upon request