Two people in hospital after car and van crash leaves A388 blocked in Cornwall.'This was broadcast to their hundreds of followers, probably all other children the same age. 'I have recently been shown screenshots of a video of two 13-year olds in Plymouth having sex which was added to their Snapchat story. The concerned mother said: 'Parents need to be more vigilant and aware of what their children are doing on social media. One Plympton resident, who wished to remain anonymous, said she was shocked to see the video had been shared among young people in the area, reports the Plymouth Herald.