The 57-year-old pleaded guilty to five representative charges of theft by a person in a special relationship and was sentenced to six months' community detention when he appeared in the Dunedin District Court yesterday.
With interest and lawyers fees included, his parents' estate lost $316,322 due to his actions.
Couper's mother Roberta, a double amputee who died in June, had said she did not want her son imprisoned for the breach of trust and it was those wishes that saved him from a custodial sentence, Judge Kevin Phillips said.
When she went into Birchleigh Residential Care Centre in Mosgiel in 2008, her husband Peter followed soon after, when he developed dementia.
Their family home was sold for $246,000 and Couper was given enduring power of attorney over the funds.
Aside from payments to Birchleigh, the elderly couple's personal spending all but dried up by the end of 2009.
But Couper, who had lost his job, had access to the accounts, cards, and PINs and he bled them dry.
The defendant was given the job of overseeing his parents' accounts because of his background in accounting but his brother was cautious about giving him free rein, asking to check bank statements as early as 2010.
But Couper repeatedly made excuses and the embezzlement became a near daily occurrence.
Over a five-year period, he made 833 dishonest transactions.
Judge Phillips called it ''relentless''.
The summary of facts broke down the different areas of his life in which Couper spent his parents' money.
While shopping at supermarkets for them, he helped himself to a variety of goods, paying with their bank card.
At New World, he bought sauvignon blanc, dark beer, cheese, crackers and condoms, the investigation found.
Couper also spent up at The Warehouse, purchasing fishing equipment, ice cream, milk, chocolate and DVDs - $1110 in 13 trips.
But that was small fry compared to other areas of illicit spending.
Couper splurged nearly $5000 on meals and drinks, $2500 on vehicle repairs and servicing, $7500 on homeware and $7000 on school and sports fees for his children.
Where the sum really blew out was when he brazenly diverted more than $40,000 to cover his mortgage and nearly $120,000 in direct debit transfers to his own bank account.
''Your mother is not here to see the shame of her son standing here in the dock before me,'' the judge said.
Counsel Cate Andersen said her client had been unable to make things right with his mother before her death.
He had, however, met his sister at a restorative justice conference and the court heard she too wanted Couper to stay out of prison so he could work on paying back the debt.
After selling his home, the remaining amount owed was $36,729.
Judge Phillips ordered he pay it back at $120 a month.
At that rate, Couper would be 82 before the debt was settled.
As well as community detention, the man was given 400 hours' community work and nine months' supervision.
Where the money went
New World: 49 transactions — $2736
Countdown: 46 — $2200
CSC (tobacco store): 43 — $2200
Service stations: 55 — $3319
The Warehouse: 13 — $1110
Eateries: 160 — $4778
Vehicle/mechanical: 8 — $2583
School/sports: 20 — $6964
Accommodation/building work: 13 — $5270
Mortgage: 31 — $40,850
Direct debits: 317 — $118,877
ATM: 59 — $10,350
Visa: 19 — $5802
