Three teens played a game of scissors-paper-stone to decide who would be first to rape a 13-year-old girl.
After Bryan Ong Jing Chong won, he pulled the victim, who was resting, off a bunk bed. But he did not have sex with her and instead pinned her down on a mattress together with Tan Wei Guang.
Alson Tan Yu Seng then penetrated her without a condom.
Tan Wei Guang, now 20, was sentenced to reformative training yesterday for abetting Alson Tan in committing the offence.
Alson Tan and Ong, both 18 now, were also sentenced to reformative training earlier this year.
Offenders sentenced to reformative training have to spend between 18 months and three years in a reformative training centre. They must also follow a strict regimen that includes foot drills and counselling.
The victim actually had a crush on Tan Wei Guang, after getting to know him through Facebook some time in 2013.
In December 2013, she met the trio at the basketball court near Alson Tan's flat in Senja Road. All four later went back to his flat, where the three boys discussed the idea of having sex with her, without her knowledge. Alson Tan revealed to his friends that he had seen the headman of his gang, Koh Rong Guang, now 24 , raping her.
Deputy Public Prosecutor Stella Tan said: "Alson then suggested to Bryan and the accused that they could have sex with the victim. The accused and Bryan agreed to his suggestion and played scissors-paper- stone to determine the sequence of who was to have sex with her."
They then went to the bedroom and attacked her. They stopped and released her only when they heard Tan Wei Guang's brother knocking on the bedroom window.
Tan Wei Guang's lawyer, Mr Gino Hardial Singh, told District Judge Eddy Tham yesterday that his client would like to defer his sentence by two weeks as he wanted to spend more time with his newborn son.
Tan Wei Guang is now out on bail of $20,000 and will surrender to the court on Sept 12. For abetting rape, he could have been jailed for between eight and 20 years, with at least 12 strokes of the cane.