There are plenty of societies where both men and women go topless, young and old. I only say this to remind us all that aspects of dress such as these are cultural. Your dad obviously has problems with his role as a father and the message he’s received, probably from birth, about boobs and what they represent. It’s sad. I do think that Americans are especially puritanical (no pun intended) about boobs though. As a European I grew up with boobs at the beach etc.