Your answer would be false
Family and friends may encounter a host of negative mindsets and emotions as a result of their loved one’s substance abuse or addiction. They may begin to blame themselves in a capacity that erodes their sense of self-worth or self-love.
Criminal law corresponds to part of society and societal regulations where different aspects of law have been broken and people who are considered to be guilty are then judged by. Criminals are therefore judged based on criminal law which state how severe their sentence should be.
Civil law on the other hand, however, corresponds to parts of society where we're talking about common people/citizens, different aspects of civil life which tell us what is allowed and what is not allowed.
They can if they want to, but if they do they will infect whoever they are doing it with. No one can stop them. But if you are looking for a definitive answer then no, it is not okay at all because of the risk they are putting other people at. Especially because STDs are with you forever, they never go away.
Hope this helps!!