Welcome to the STD forum, and congratulations for following safe sex practices and for being concerned about your girlfriend's health. (Of course your concern for a regular partner's STD risks should be just as great whether the steady partner is male or female.)
They call them STDs because you have to have sex to transmit them -- and for disease transmission purposes you did not. With only various kinds of skin-to-skin contact and fingering, and no unproted penile insertion into rectum or mouth, there is little potential for transmission. These activities may not be truly zero risk, but the chance of transmission is low enough to be disregarded. To the specific questions:
1) STD risk? Near zero.
2) Usually 2-3 days for gonorrhea, 7-14 days for chlamydia, 3-10 days for herpes, 2-3 weeks for syphilis, 6+ weeks for HPV/warts.
3) Warmth and humidity contribute to spread of staph and other skin bacteria in bath houses, but there is no evidence such environments enhance STD/HIV trasnmission.
4) "Should I get tested?" is a social issue, not a medical one. From a risk assessment perspective, people whose sexual practices are limited in the way you describe don't need routine testing at all, unless symptoms develop. But if this reassurance doesn't completely settle your fears, you could be tested. It's up to you.
This is not a relationship counseling service. However, if you have not informed your girlfriend of your bisexuality, it might be appropriate for you to do so. For most men who have sex with men, it is difficult to limit sex to non-insertive practices. If and when you get tempted to have anal or oral sex with other men, your partner will be at risk -- and which point she has the right to know the risk exists.
Regards-- HHH, MD
Wow ! Thank you for answering so fast !
I'm still puzzled by the fact I saw ads about herpes prevention mentionning the fact that :
1) People may be contagious even when they do not have an outbreak ;
2) The contagious region is whatever can be covered by boxer shorts.
What should I make of that ?
I also regularly read stuff about hand-to-genital transmission. How come this web site is the only so radical about it being a no-risk activity ?
Finally, for the benefit of everyone reading your answer, if the risk is near zero, which STDs make it not zero ?
You are absolutely right about my relationship with my girlfiend. My «secret» gets in the way of a true relationship, and healthy lifetsyle. I am working on this side of the equation.
Thank you very much.
What you "should make of that" is nothing. HSV simply is not transmitted by the sorts of exposure you describe, at least not with measurable frequency. The risk may not be zero, but it's close enough. Although recurrent herpes outbreaks can appear anywhere in the boxer shorts area, asymptomatic viral shedding is pretty much limited to the genitals or anus.
This website takes into account probabilities, whereas many others -- certainly most of those run by health departments and many other agencies take an absolutist position at the advice of their attorneys; if there is any risk at all, mention it, typically without context.
The theoretical some-risk STDs in this situation are HSV and HPV.