It's important to dress appropriately for the weather. Layers are a great and highly adaptable way to go. The sweater/hoodie/t-shirt combo is a winner allowing anywhere from one to three layers in the course of a day. Similarly wearing zero to one layer(s) from the waist down is also a solid option.
Because you never know when you want to flash you dick and sack in public while pretending you're not.
On a related note, I have jeans like this and was going to have them mended. Perhaps I still will but will patch them with a picture of a dick busting out of denim. It will make hunky crotch-watching guys think I'm exposing myself but should I run afoul of the long arm of the law, I can show them that all I'm exposing is artistic expression.
As for this guy, I would tell him "Don't ever change."