Bro, consider not everyone on the internet is a man, and also that the joke was that he literally put his ring in her vagina, so my (or even his) fingers have nothing to do with anything (because I seriously doubt he was making a reference to fingering his wife)..
Still, if I was planning an evening of sexy times that might get digital, hygiene considerations would include cleaning the ring separately (assuming the ring was going to be involved at all).
This might be the issue. Unless you separately wash the ring, bacteria will almost certainly remain along the edges of the ring after washing your hands.