Read the body language…
… is it obvious what’s going to happen next? Check behind the cut to see if you were right!
So this is what happened next:
Okay, I’m cheating a bit because this is obviously a picture taken on a different day. However, the scenario was exactly the same. Whenever I announce that we’re going to the park, Bowdu gets revved up and feels compelled to vent his excess energy on Bowpi.
From Bowpi’s wide eyes, pinned ears, slight piloerection (hackles barely visible in the top picture), nervous lip-licking, stiff posture, and yawn in the bottom picture, she’s obviously not thrilled about his reaction to the situation.
But though she appears on the verge of snapping, she usually tolerates his effusiveness.
When I first noticed Bowdu’s tendency to move in for a hump, I acted on what I perceived as Bowpi’s discomfort. Honestly, there wasn’t much reason to intervene other than that I found it vulgar to watch. After all, both pets are fixed, and this is a normal part of dog-to-dog communication. It’s arousal, but in this case it’s not sexual. Bowpi would grumble, but she wouldn’t really try to move away or resist. Thus it was especially offensive to my human and even feminist sensibilities when he’d wrap himself around her lovely white neck and thrust against her poor little head with wanton zeal.
Eventually, I just let them act according to their natures. After a while, I noticed an additional, unexpected response — once released, Bowpi would lick her lips and grumble a little, but then she’d tiptoe up against Bowdu’s side, and he’d mouth her face or lick her ears in a more “conventional” display of affection.
Somehow, letting Bowdu hump Bowpi to his heart’s content changed their relationship, creating new parameters for physical contact. Which is not to say Bowpi always lets him get his way. Once every four or five times, she really doesn’t feel like getting humped, and she will nip or snark to tell him so. And he heeds her. I think he learned to accept her rejections because he benefits from her compliance most of the time.
Kudos to NYEarthling and Losech for calling it in the comments!
Addendum — a couple good links about humping: