STIs are transmitted by oral to genital contact - think oral sex, unclothed or unprotected genital to genital contact, or unclothed or unprotected anal to genital contact.
That's it. Mutual masturbation and breast to genital contact is not a risk.
Here are some posts from our experts (when we had them) that may help -
https://
www.medhelp.org/posts/STDs/Nervous-about-mutual-masturbation/show/2183476
https://
www.medhelp.org/posts/STDs/Mutual-Masturbation-STD/show/1968429
https://
www.medhelp.org/posts/STDs/mutual-masturbation-sti/show/1858544
https://
www.medhelp.org/posts/STDs/Understanding-the-risks-of-mutual-fingering/show/1516796
https://
www.medhelp.org/posts/HIV---Prevention/Vaginal-fluid-on-hand-touched-inside-of-condom-and-head-of-penis/show/1119533 - read this thread thoroughly. There is an excellent explanation about why certain activities are not risks, and why others are.
You only need to ask the questions once. Someone will be along to answer you. And please keep your questions in one thread so we can keep track of your history - it's a lot easier for us that way. :)
Between breast als no risk? Even for syfilus , herpes, hpv?