A French teenager facing criminal charges in Singapore for a straw licking stunt was granted permission on Wednesday to leave the country for three weeks on pledges to return.

The 18-year-old is accused of posting to social media a video of himself putting the straw he licked back into the dispenser on an orange juice vending machine.

Didier Gaspard Owen Maximilien’s clip went viral and triggered a backlash that led to his arrest in Singapore, which has a reputation for not tolerating bad...