(Strip Number 603, Original Publication Date, 30 April 1984)
Panel 1: As our story continues, we find ourselves watching Phil as gives Michael his first trumpet lesson. It would appear that he's trying to get Michael's embouchure correct because he's telling the little dude to press his lips together on the mouthpiece and blow the same way he does. While Phil can play something musical, Mike's just starting out so still sounds like Radar O'Reilly does when he's playing Reveille.
Panel 2: Pointing to his own lips, Phil smiles and tells Mike "Check out my lip....all muscle! A horn player's face is all muscle."
Panel 3: Just then, John walks in and asks how the introductory lesson is going. Michael says that it's going okay.
Panel 4: The reason it's going okay is because Uncle Phil was just telling him that his head is all muscle. Since Phil isn't used to how small children make a hash of what they're told yet, he's mildly confused.
Summary: Since he doesn't understand that fact of life what with being a bachelor who doesn't have much experience dealing with kids, he's going to have to endure a lot of incidents like this. At least with him, this sort of thing makes sense. It would make no sense at all were he a thirty-five year old mother of two. (See what I did there?)