Most STD do not live well outside the body and if he had anythng on him then the chances of it passing something on to you are very slim if not zero.
Now if he is not using condoms with the other person (if there is another person) then if you don't use a condom then you could get something if he has something. Vaginal and anal sex are the best ways to transmit STD but you can also get it from giving oral sex. A lot less risk from oral sex but still a risk.
if his pubes rubbed on my vaginal areas can i get infected