If you are going to play your are going to get burned.
Sooner or later. First, there is a lot of BS that STD's are only transmitted having sex. Actually it is the liquids containing the STD's in the sexual body fluids that are transmitted. The little germies just don't hop out and in when you do it. So get those liquids from one body into another and there you have it, disease transmitted. Doesn't matter how you did it.
Question is, does it have to get into the blood stream or can swallowing or putting your fingers in your mouth, near your nose etc do the trick. In World War II, the one group was known to give diseases to prisoners by rubbing a feather under their noses with the diseases on them. So lets get the transmission cycle down pat. It is just not sexy ways that cause transmission, just move the body fluids from source to victim.
If you search around on the net, you will find evidence of disease being transmitted by wet towels and face cloths. Trichonomasis can be easily transmitted by such, but I had a doctor tell me you could only get it if you really got your tool into a woman. BS, oral will transmit it as well any moisture into the wrong place. So let Peter dangle when you wash him afterwards so as not to force water into his little tube.
There is a more insidious transmission route. When you have sex and rub your pubic hair against her body fluids, those little bugs(bacteria) get on your pubic hairs. Put your underwear back on and now you rub the bugs off on the underwear, and guess what the underwears are rubbing on as you walk along. Bingo, transmission, no bareskin, but you got sick anyway. This route bypasses condoms very effectively. Not good for transmitting many diseases but works well on others. Want to test it out? Take a shower afterwards to prevent it.
Doing digits? Be careful about putting them near your nose, or mouth. Some girls will give you Purine hand wash for before and after.
Yes condoms prevent infections very well and must be used. Cleanliness and care will complete the cycle. You can't relax in these areas.
Now that you have read all this, maybe you want to be extra careful.
After leaving a lady, within a few days, or maybe even hours, do you feel some discomfort. Don't mess with it, get to a doctor quickly, or the STD clinic listed in your phone book, confidential, and just confess your sins. Meanwhile, don't hug, kiss or shake hands with anyone. Wash your underwear on the sani cycle.