This chapter presents a case study Gary who is 18-year-old car mechanic. Gary has a varied sexual history and has boasted about having more than 15 sexual partners since his introduction to sex in his early teens. Accordingly, the definitions of 'sex', 'sexual activity' and 'risky sexual behaviour' need to be extended and clearly defined, for both the healthcare professional and the Individual. The UK government has spent millions of pounds on promoting 'safe sex' and has promoted the use of condoms as preventing sexually transmitted Infections. Sexually transmitted Infections can be prevented by condom use, but a 2009 survey Indicated that Individuals are less likely to use condoms for this preventative purpose, with 90 per cent of men and 89 per cent of women citing prevention of pregnancy as their reason for using condoms, and only 45 per cent citing prevention of Infection, most of whom cited pregnancy Infection as well.