> The virus enters the body primarily through broken skin (even if not visible), or the mucous membranes (eyes, nose, or mouth). Human-to-human transmission is thought to occur primarily through close contact with an infected subject. There are indications that transmission is occurring during sexual intercourse
as far as I know COVID is not transmitted primarily through broken skin, so it does seem more likely to be transmitted through sex.
You are technically correct about covid. However - and this was my point - if you have sex with someone with active, transmissible covid without substantial and properly fit PPE you are probably going to catch covid. It doesn't matter what type of sexual behavior you engage in, or what safer sex precautions that you take. That does not make covid an STI.