Thanks for your questions.
1. You don’t need to worry about being exposed to HIV this way. HIV is not transmitted through skin-to-skin contact like you’re describing – HIV dies in seconds when it is exposed to air, so it will not live on the outside of skin. HIV lives in a few specific body fluids: vaginal fluid, semen (cum), blood, and breastmilk. We consider it a possible exposure if one of these fluids gets directly into an opening in your body – either the urethra (pee hole), cervix (inside a woman’s vagina), the anus, or a puncture wound (like a needle stick). HIV won’t be transmitted through body rubbing or washing, mutual masturbation (hand jobs) or protected oral sex.
2. You are quite unlikely to be exposed to other STIs this way as well. Most STIs are not passed by mutual masturbation, body rubbing, or protected oral sex. Even those that are passed from skin-to-skin (like syphilis, herpes or warts) are generally passed by genitals rubbing together, not through being touched by a person’s hands.
As you probably saw on my chances, it is not quite uncommon to get herpes from protected oral sex. If the CSW had herpes, and her mouth rubbed against the skin at the base of your penis, which was not covered by the condom, there could be a possibility of transmission. This can happen even if someone does not have a visible outbreak. Again, this is not that common, especially in a one-time exposure.
3. Although these activities are low risk, it’s great that you are getting tested and thinking about your current partner. I’d encourage you to talk to your health care provider about what tests are included in your STI screening.
I don’t see any reason to be concerned about sex with your partner, especially if it is with a condom. I guess it is possible to pass on herpes if you caught it, but this is not very likely from a one-time exposure through oral sex with a condom.
I hope that helps answer your questsion – let me know if there is anything further I can clear up!