Panel 1: We see Phil stand there looking like a gaffed trout because Mike and Liz are arguing about what to watch. This means that he's forgotten that he and Elly used to do the same damned thing.
Panel 2: He then stands there looking traumatized because Unknown Baby From Nowhere is screaming for food. Seriously. He has no idea that he's an uncle all over again because no one thought to tell him.
Panel 3: As Elly picks up Unknown To Phil Baby He's Just Learned About, she asks if he wants another cup of coffee. When he says that he'd rather head home, she wonders why he's leaving so soon.
Panel 4: It's his turn to be gobsmacked when she says that she thought he'd hang around and relax.
Summary: He needs more married friends. If he had more married friends, he'd learn that not all children are horror monsters like the Patterspawn.
Also, this seems like a really ham-fisted way of consoling a man with a low sperm count and/or a woman with fertility issues.