It's not so much the indignity for Herbert as it is his unwillingness to be potentially caught by someone or something while trapped with his pants around his ankles. It's perhaps more dangerous here than he'd thought. How annoying, to be caught in the midst of someone else's battle.

So, he does follow, yes, his expression growing ever more unimpressed at what he perceives to be Foster's distractability.

"We're touching the floor," he says flatly in response, although it's one of his jokes. It just comes out as sardonically as he says most other things. "Are you in the habit of prodding random spiders? Or should I be watching my feet?"