No, you definitely don't need pep. That is reserved for someone that has a true risk with someone known to be HIV positive. You didn't risk HIV from your encounter. Pushing your penis up against including your urethra will not result in HIV transmission. Air is present. The only risks for HIV are to have unprotected vaginal sex or anal sex or share IV needles to inject drugs. Oral is not risk. Air and saliva both inactivate the virus. So, you do not need to worry.