How to convince my husband to cut his long hair?

Ok So my husband is in his early 40s he has long hair past his shoulders and quite honestly its awful, he has a DEEP widows peak and so when his hair falls to side it looks like he’s bald on the sides of his head but he’s not it’s just his natural hair line, his hair keeps thinning and it’s looking worse and worse, the weight of his hair caused the top to flatten and actually makes him look like he’s loosing hair way more then he actually is, if he cut it like a normal men’s hair cut it would look a million times better and way fuller the problem is he’s got ptsd from childhood when he tried to grow his hair out his dad beat him up his uncles held him down and shaved his head, so now 25 years later any mention or polite suggestions about him cutting it are met complete disdain and anger, what do I do? How do I trick him into thinking it’s his idea, it looks bad guys he looks really white trash and it’s always oily and he’s always struggling to keep it under control, I don’t get it, when I met him his hair was short and normal and he looked great

How to convince my husband to cut his long hair?
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