He was furious when the ex-boyfriend of the girl he was going steady with registered a "like" for a comment she had made on her Facebook page. So Marc Brandon Bignalen Sim tried tracking down the man he knew only as Hairee.
When he met Mr Benson Aw Jun Hong, who was Hairee's friend, things turned bloody. On Friday, Sim was sentenced to reformative training for slashing Mr Aw with a knife. Both men were 20 years old and full-time national servicemen at that time.
A district court heard that Mr Aw had agreed to meet up with Sim at a block of flats in Yishun at about 8am on June 15. When Mr Aw refused to hand over Hairee's telephone number, Sim pulled out a knife with a 20cm blade and slashed him four times on the legs.
He then fled and the victim called the police. The injuries were so serious that Mr Aw suffered a fracture of his right leg and had to undergo two operations.