Parents are being urged to know the potential dangers VR headsets pose for their children, ahead of the Christmas holidays.
The popular technology, which sees gamers wearing a headset over their eyes, transports the wearing into a virtual world.
But children's advocates are concerned that parents are unaware of what goes on inside these new and unchecked 3D worlds and chatrooms.
Childline has released a scary encounter one secondary-school-aged girl had while inside the metaverse.
The charity said young people had shared their experience of online VR with its phone-in counselling service.
One student said: "Recently I met a guy on my VR game, and I'm confused about how I should feel about him.
"He's really bad, like he always makes sexual comments towards me and asks me to 'kiss' him in the game.
"I know that's messed up, but I love his voice, and he makes me feel like the person I'd rather be.
"Nobody gives me that kind of affection in the real world. I guess that's why I use VR, so I can look and be like someone I'm not, and it makes me feel good about myself.
"I think I like this guy, but I don't know if he just likes the character I play as online."
Kate Edwards, acting associate head for child safety online at the NSPCC, said: "Parents who may be thinking about purchasing a VR headset for their child this Christmas need to be aware of the risks young users currently face when given access to what, at this stage, is an unregulated world."
Polling for the NSPCC showed that while one in five parents would buy a VR headset for their child if they could, more than two-thirds of the public lack confidence that child safety is a priority in the metaverse.
Ms Edwards said: "But this responsibility should not just be on parents.
"Tech companies must do more to ensure the safety of children on existing products, as well as for ones they roll out in the future.
"And the government needs to deliver a robust Online Safety Bill that accounts for advancements in technology and ensures new devices and platforms are created with child protection at their heart."
The NSPCC has compiled a list of tips to help keep children safe when using VR:
• Make the headset a family activity, taking turns and playing with it together
• Take some time to explore the headset yourself before allowing a child to use it
• Familiarise yourself with any safety features, such as parental and privacy controls
• Talk to children about how they use VR and ensure they know not to share personal information
• Set healthy boundaries when it comes to playtime
