A British Army Guardsman who stole his best friend's Armani watch was caught when the troop's girlfriend played detective and found him trying to sell it on Gumtree.
Guardsman Callum O'Donovan-Cronin returned from guard duty to find his prized possession gone and reported the £350 timepiece missing, a military court heard.
Having spotted an identical watch posted online, he and his girlfriend hatched a plan to catch out the seller.
In a sting operation they reached out to 'James, from Woking', who they suspected might be close friend, Gdsm James Howard, of the Welsh Guards.
Bank details confirmed their hunch that it was in fact Gdsm O'Donovan-Cronin's pal.
Now, after admitting a single charge of theft, Howard has narrowly avoided dismissal, with a judge sentencing him to four months service detention, suspended for 18 months.
Prosecutor Colonel Grant Davies told Bulford Military Court, Wilts, Gdsm O'Donovan-Cronin had bought the watch for £350 in October 2022.
"On December 19 last year the victim returned from guard duty and found his watch was missing and reported it so," he said.
"Several days later, he and his girlfriend were watching TV, and saw an identical watch being sold on Gumtree for £90 by a person called James in Woking.
"He described himself as cross, visibly shaking and angry."
As their plan unfolded and bank details confirmed the identity of the thief, Gdsm O'Donovan-Cronin messaged Gdsm Howard who admitted stealing it, saying: "I'll be honest, I'm broke, I know it's shit of me."
The court heard 26 year old Gdsm Howard had entered his colleague's room to socialise, but in a 'moment of madness' saw the watch and took it.
The father of two was struggling financially and hoping to make a bit of extra cash in time for Christmas, it was heard.
Mitigating, Chris Cannon told the court Gdsm Howard understood theft from fellow soldiers was 'corrosive to morale and trust'.
"It was an impulsive act," he said.
"It wasn't planned - he didn't even know it would be there - and it was certainly an unsophisticated method to sell it."
The court heard the two remain 'good friends', with Gdsm O'Donovan-Cronin having held 'no grudge'.
Addressing Gdsm Howard, Assistant Judge Advocate General Jane England said theft from fellow service personnel was enough to 'warrant' dismissal, but not to act on it in this case.
"This was a serious breach of trust," she said.
"You know as well as anyone service personnel need to rely on the honesty of others not to steal from one another.
"Whenever anyone steals from a work place you can expect to be dismissed, and the Army is no different.
"It seems the motivation was to being in debt and wanting to give your daughters a decent Christmas which you couldn't afford."
The judge said theft offences 'drive coach and horses' through the trust which service personnel must have with one another.
However, she credited his 'obvious remorse', cooperation and early guilty plea, as well as his offer to give the watch straight back to Gdsm O'Donovan-Cronin as soon as he was exposed.
"Balancing all these factors, we have decided to allow you to soldier on," she concluded.
"There is a prospect of you providing valuable service to the Army - allowing us to give you a second chance."
Gdsm Howard, based at Combermere Barracks, Windsor, was therefore sentenced to four months service detention, suspended for 18 months.
Following the sentencing, Gdsm O'Donovan-Cronin was reunited with his Armani watch.
