What do you do when someone is obviously pretending to listen to you?

[MrsMerryHenry]

I knew someone who used to talk gibberish, then wait for a response. Invariably, the mind-wanderer would reply: 'oh, yes, of course. Hmm, I thoroughly agree'.

Could you do that? What do you do? Or what would your sharp-witted alter ego do?

I transition into saying something outrageous in the same tones "Right so DH, we need to buy cat food, clean the kitchen floor, and did I tell you what the bishop did to me in the rose garden.." Usually wakes him up