The safest form of sex is no sex at all
Any kind of sexual practice carry some risk, from really low to major.
Even really low risk carrying activities could change into big risk activities if anything happens in between. A little nail scratch, some lipstick on the condom that could cause tiny holes in it, touching condoms with oily hands etc.
Heck, even sitting on some toilet could give you something if unluckly.
So, my advice, for everyone, just do what makes you happy and if you feel the risk is too big
don't take it.
If you are someone that's always prone to get sick and get infection just stick to one regular partner or simply masturbate, you're very likely to catch something at some stage if you do otherwise. If your imune system is strong (like mine
), use your cop on for anything you do. Information about how STDs works and spread, wise decisions regarding partners and activities, together with a lot of doctor checks are usually working best for most people.