Pinworms are a childhood disease and self limiting, adult immune systems generally defeat them, and the trap would know if he still had them because his butthole would be itchy all the item.
Their lifecycle unironically relies on scratching your butthole which has worm eggs on it (the worms come out and lay eggs on your rectum) and then swallowing them>who would do that?
Literally children. It's also why a treatment (in third world countries) is to clean the anus and try to dislodge any worms in the process of laying eggs.
The story is almost certainly fabricated, and even if it isn't, of infinitely greater concern is getting some other STDs. Furthermore, there are unironically pathogenic organisms that exist inside vagoos that will swim up a man's urethra and colonize his bladder and then transmit themselves to other women.