A Singapore Armed Forces (SAF) regular was sentenced to 15 months jail for having sex with a 13-year-old girl.
The girl's parents had found Tan Yong Jin, 24, along their daughter in their flat.
They were already dressed when the girl's parents had found them, reports The Straits Times.
The teenager, who cannot be named, admitted to having taken part in sexual activities with him.
Her mother then alerted the police.
Officers then turned up at the flat to arrest him.
Tan was sentenced yesterday (Jan 11) after pleading guilty to two counts of performing consensual sexual acts with the child, who was a Secondary 2 student at the time.
The two had met on Facebook in 2016, where they became friends.
Deputy Public Prosecutor Amanda Chong said he was aware that she was under 14.
The pair stayed in contact after meeting for lunch later that month and began to exchange sexually charged messages.
On Jan 8 last year at around 11am, the girl asked Tan to meet her at Clementi Mall. Two hours later, they went to a nearby cinema.
After the movie at around 3.30pm. they took a bus to the girl's home in Jurong to have sex as her parents were out.
DPP Chong said: "They were not in a boyfriend-girlfriend relationship. Upon reaching her residence, the victim made a check to confirm her parents were not at home before leading the accused up to her residence. Inside her residence, she led the accused into her parents' bedroom."
The SAF sergeant then had unprotected sexual intercourse with the girl and she also performed oral sex on him.
District Judge Wong Li Tein said that Tan "should have known better".
For each count of sexually penetrating the minor, Tan could have been jailed for up to 20 years and fined or caned.