That's a really silly distinction you're trying to make. So you're saying that it's okay for people to have to see this even if they want cheating filtered?
It's game mechanics. Admirals can give oath rings to the girls. It's not possible to prove there is cheating happening in the scene.
It's a wedding ring, not an oath ring. Don't use the english localization to justify removing the tag when it visually fits. If you're that sure about it, why not ask the artist themselves?
Seriously dude, everyone knows it's good hygiene to take off any rings before you stick your fingers in someone's asshole... what don't you get about this?