The answer is...
B. Buffers
Protozoa-
Cholera
Malaria
Amebic Dysentery
Fungi-
Ringworm
Athlete's foot
Histoplasmosis
Rickettsiae-
Typhus Fever
Rocky Mountain Spotted Fever
African Tick Bite Fever
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!!
Dog sledding I just looked the answer up trust me