Partner play safety

[FNG]

Hello, I have some questions about using this safely with a partner. Specifically, if only one person is connected to a unit, how much worry is there over the other person touching them and getting a dangerous shock? For example, if the partner is not touching anywhere between the electrodes, should that be safe? If the person is wearing underwear that covers all of the electrodes, is it safe to touch anywhere outside of that covered area, or even over it?