One Sunday afternoon, David, his friend Chris and Chris's girlfriend Nikki decide to go camping in the countryside. On the train there, they meet Jason. Although the group have never met Jason before, he and David seem to hit it off and so David invites Jason to join them.

When evening falls, David invites Jason to share his tent and they have unprotected sexual intercourse. David fails to tell Jason that he is HIV positive. Meanwhile, Chris and Nikki decide to spend the night in a nearby hay barn. Nikki finds an old branding iron and asks Chris if he would like her to brand her date of birth onto his back. He agrees and she brands him. After this, with Nikki's consent, Chris carefully inserts some sterilised needles that he has brought with him through each of Nikki's nipples. Both find this sexually stimulating.

Discuss any potential criminal liability arising.