I understood you meant with somebody. The same rules apply in a shower as they do on a bed or anywhere else for that matter.
It depends on the level of sexual contact that occurs. Hence why I mention mutual maturation and how that wouldn't be classed as risky.
If you were to have sex, use protection like you would normally.
I mean showering WITH someone.
Thanks, how does showering depends? On what??
With regards to HSV-1, that is all assuming she would even have the virus and that you don't already have it yourself.
Kissing poses no risk for transmitting STIs unless you include oral HSV-1 which isn't classed as an STI. This would only be spread by passionate kissing and you'd only really be at much risk if there's sores present.
As for showering it depends, showering alone is risk free, there would also be no risk in mutual masturbation.