First off, there is no legal basis to claim that cheating is unacceptable.
As for ethical, what sort of "risk" are you talking about here?
If you are talking about risk of disease unless in cheating you are doing something insane, like bareback anal, the risk is negligible. You have a higher chance of bringing home a disease to the wife by visiting a daycare and having a child sneeze on you. Probably a worse disease. Sure, if you bring home an explicitly sexual disease she's going to clue into your cheating--but the stuff you're likely to bring home is curable, unless you are engaging in things like bareback anal.
If you are talking about psychological/emotional risk--I don't accept that's a risk with any ethical implications, not when it comes to sexual behavior. People engage in sexual relationships knowing that the might get hurt. That's life. Get over it. We're all hypocritical when it comes to sex, and we all know this. We play the game, because we're alive. It's human nature.
Do you engage in unprotected oral and/or vaginal sex with any of these women, in particular SPs? If you don't then fine, I accept your premise that walking into a daycare centre has about the same medical risk as sex. Personally I still think you're twisting your case around to extremes to justify your stance on the negligible medical risks, but I can accept that transmission rates for most STIs, and in particular the incurable ones are very very low in cases of protected sex. However, I'm not presuming anything, but if you engage in unprotected oral sex, then you are absolutely dead wrong on the risks. There is a vast difference between a case of herpes, that you can catch from unprotected sex, versus a common cold that you could catch in your daycare example. Physically, mentally, emotionally. If you don't see that, then there's nothing more to say. Even gonorrhea, notwithstanding the scary incurable new strain that was posted about today, which is the most easily treatable STD (I think), has severe medical risks if untreated. Also, it has more health consequences for the woman than the man. Now if you get yourself tested regularly, then that's fine, or you engage in only protected activities with your wife, but if you don't, and you engage in unprotected sex with your 'ladies' whether they be SPs, immigrants or other women, as well as your wife, then every time you engage with your wife, you're putting her at risk. Physically, the risks aren't too serious for most STDs, provided treatment is quickly provided, but mentally, emotionally? She may have signed on knowing the kind of person you were, but she definitely did not sign on for any STDs, and to compare the risks with that of having a kid sneeze on you, is laughable, and dangerous. You signed on for the risks, she didn't. If you care so little about your wife that you write off exposing her to STDs as part of the 'hypocritical nature of sexual relationships' then why even marry her in the first place?

