Not a CIDU, but commenters are invited to lay out the 1930s-era joke/prank for the benefit of others who may not recall it. The setting and backstory of this strip give a nice matrix for embedding the joke with a small but fitting fillip.
“Well, you’d better let him out!”
Comics I Don't Understand 
It’s not quite as many Xs, but will do …
. . . or waaaaay too many Xs.
This Sunday panel 2021/02/14 (Valentine’s Day) is apparently the last one for New Adventures of Queen Victoria: