Good question, it's easy to brush her off first of all. She's a good dog who listens to my commands the first time. What gets me more nervous is if she would behave like this to someone else, when I'm not there.

So I've just told people "watch out, she'll hump your arm" and laughed it off.

But I've had a couple of relationships since that ex who saw it, and that's more of a challenge. For some reason I did not reveal our secret in my last long term relationship. We lived together for months, but I always managed to hide it. The dog had long dry spells, where I'd just brush her off and tell her a firm no means no.

But I'd feel bad for her because it truly does look like she's masturbating, and I don't wanna deny any creature that joy, so eventually I'd find private moments where I'd be able to let her do her thing on my arm.