currently there isnt any kind of infestation that stays in the dick/urethrea. the three that are available travel to the balls, ass/guts, and bladder(or is it prostate?) so while there is an X-ray for the penis, there isnt anything actively wiggling around inside there while you're walking about, beyond the initial infestation and the bathroom expulsion scenes that is.
the ball and bladder infestations certainly enter through the player's penis, but they both nest further inside. i'm honestly looking forward to anything Quanzillan is planning for something that actively stays and crawls around inside the urethra as it multiplies and dangles from the tip <3 <3 but that remains to be seen as his last dev post makes it sound like he's gonna be focusing on doing overhauls on the game mechanics and storyline for the time being. so might be a wait before theres more new content