(Strip Number 1467, Original Publication Date, 23 June 1989)
Panel 1: We lurch uneasily into Elly's failed attempt at "including" Mike into the process by asking him if he'd like to hold his new sister. He agrees to do so.
Panel 2: She then tells him to hold her carefully like so and then probably prepares to saunter off for hours on end while expecting him to sit on the couch until that evil and bad feeling in his limbs that tells him that playing is good goes away forever.
Panel 3: He stares down at her as if he can almost see his wonderful future of being told that being oldest means never winning again.
Panel 4: After only a few minutes of sitting quietly, Mike yells that he's had enough. This scares Lizzie awake.
Summary: The premise, of course, is that Mike is a BAD child who no one can like because he doesn't see the point of watching other boys play while he gets stuck playing nursemaid. It never occurs to Elly that her self-serving default assumption that if it has a pulse, it's ready and willing to tend to her children to give her time to herself has a trainload of downsides. In this case, it's the other reason why Mike resents Liz forever.